xref: /openbmc/linux/drivers/isdn/mISDN/dsp_cmx.c (revision 842ed298)
1 /*
2  * Audio crossconnecting/conferrencing (hardware level).
3  *
4  * Copyright 2002 by Andreas Eversberg (jolly@eversberg.eu)
5  *
6  * This software may be used and distributed according to the terms
7  * of the GNU General Public License, incorporated herein by reference.
8  *
9  */
10 
11 /*
12  * The process of adding and removing parties to/from a conference:
13  *
14  * There is a chain of struct dsp_conf which has one or more members in a chain
15  * of struct dsp_conf_member.
16  *
17  * After a party is added, the conference is checked for hardware capability.
18  * Also if a party is removed, the conference is checked again.
19  *
20  * There are 3 different solutions: -1 = software, 0 = hardware-crossconnect
21  * 1-n = hardware-conference. The n will give the conference number.
22  *
23  * Depending on the change after removal or insertion of a party, hardware
24  * commands are given.
25  *
26  * The current solution is stored within the struct dsp_conf entry.
27  */
28 
29 /*
30  * HOW THE CMX WORKS:
31  *
32  * There are 3 types of interaction: One member is alone, in this case only
33  * data flow from upper to lower layer is done.
34  * Two members will also exchange their data so they are crossconnected.
35  * Three or more members will be added in a conference and will hear each
36  * other but will not receive their own speech (echo) if not enabled.
37  *
38  * Features of CMX are:
39  *  - Crossconnecting or even conference, if more than two members are together.
40  *  - Force mixing of transmit data with other crossconnect/conference members.
41  *  - Echo generation to benchmark the delay of audio processing.
42  *  - Use hardware to minimize cpu load, disable FIFO load and minimize delay.
43  *  - Dejittering and clock generation.
44  *
45  * There are 2 buffers:
46  *
47  *
48  * RX-Buffer
49  *                 R             W
50  *                 |             |
51  * ----------------+-------------+-------------------
52  *
53  * The rx-buffer is a ring buffer used to store the received data for each
54  * individual member. This is only the case if data needs to be dejittered
55  * or in case of a conference where different clocks require reclocking.
56  * The transmit-clock (R) will read the buffer.
57  * If the clock overruns the write-pointer, we will have a buffer underrun.
58  * If the write pointer always has a certain distance from the transmit-
59  * clock, we will have a delay. The delay will dynamically be increased and
60  * reduced.
61  *
62  *
63  * TX-Buffer
64  *                  R        W
65  *                  |        |
66  * -----------------+--------+-----------------------
67  *
68  * The tx-buffer is a ring buffer to queue the transmit data from user space
69  * until it will be mixed or sent. There are two pointers, R and W. If the write
70  * pointer W would reach or overrun R, the buffer would overrun. In this case
71  * (some) data is dropped so that it will not overrun.
72  * Additionally a dynamic dejittering can be enabled. this allows data from
73  * user space that have jitter and different clock source.
74  *
75  *
76  * Clock:
77  *
78  * A Clock is not required, if the data source has exactly one clock. In this
79  * case the data source is forwarded to the destination.
80  *
81  * A Clock is required, because the data source
82  *  - has multiple clocks.
83  *  - has no usable clock due to jitter or packet loss (VoIP).
84  * In this case the system's clock is used. The clock resolution depends on
85  * the jiffie resolution.
86  *
87  * If a member joins a conference:
88  *
89  * - If a member joins, its rx_buff is set to silence and change read pointer
90  *   to transmit clock.
91  *
92  * The procedure of received data from card is explained in cmx_receive.
93  * The procedure of received data from user space is explained in cmx_transmit.
94  * The procedure of transmit data to card is cmx_send.
95  *
96  *
97  * Interaction with other features:
98  *
99  * DTMF:
100  * DTMF decoding is done before the data is crossconnected.
101  *
102  * Volume change:
103  * Changing rx-volume is done before the data is crossconnected. The tx-volume
104  * must be changed whenever data is transmitted to the card by the cmx.
105  *
106  * Tones:
107  * If a tone is enabled, it will be processed whenever data is transmitted to
108  * the card. It will replace the tx-data from the user space.
109  * If tones are generated by hardware, this conference member is removed for
110  * this time.
111  *
112  * Disable rx-data:
113  * If cmx is realized in hardware, rx data will be disabled if requested by
114  * the upper layer. If dtmf decoding is done by software and enabled, rx data
115  * will not be disabled but blocked to the upper layer.
116  *
117  * HFC conference engine:
118  * If it is possible to realize all features using hardware, hardware will be
119  * used if not forbidden by control command. Disabling rx-data provides
120  * absolutely traffic free audio processing. (except for the quick 1-frame
121  * upload of a tone loop, only once for a new tone)
122  *
123  */
124 
125 /* delay.h is required for hw_lock.h */
126 
127 #include <linux/slab.h>
128 #include <linux/delay.h>
129 #include <linux/mISDNif.h>
130 #include <linux/mISDNdsp.h>
131 #include "core.h"
132 #include "dsp.h"
133 /*
134  * debugging of multi party conference,
135  * by using conference even with two members
136  */
137 
138 /* #define CMX_CONF_DEBUG */
139 
140 /*#define CMX_DEBUG * massive read/write pointer output */
141 /*#define CMX_DELAY_DEBUG * gives rx-buffer delay overview */
142 /*#define CMX_TX_DEBUG * massive read/write on tx-buffer with content */
143 
144 static inline int
145 count_list_member(struct list_head *head)
146 {
147 	int			cnt = 0;
148 	struct list_head	*m;
149 
150 	list_for_each(m, head)
151 		cnt++;
152 	return cnt;
153 }
154 
155 /*
156  * debug cmx memory structure
157  */
158 void
159 dsp_cmx_debug(struct dsp *dsp)
160 {
161 	struct dsp_conf	*conf;
162 	struct dsp_conf_member	*member;
163 	struct dsp		*odsp;
164 
165 	printk(KERN_DEBUG "-----Current DSP\n");
166 	list_for_each_entry(odsp, &dsp_ilist, list) {
167 		printk(KERN_DEBUG "* %s hardecho=%d softecho=%d txmix=%d",
168 		       odsp->name, odsp->echo.hardware, odsp->echo.software,
169 		       odsp->tx_mix);
170 		if (odsp->conf)
171 			printk(" (Conf %d)", odsp->conf->id);
172 		if (dsp == odsp)
173 			printk(" *this*");
174 		printk("\n");
175 	}
176 	printk(KERN_DEBUG "-----Current Conf:\n");
177 	list_for_each_entry(conf, &conf_ilist, list) {
178 		printk(KERN_DEBUG "* Conf %d (%p)\n", conf->id, conf);
179 		list_for_each_entry(member, &conf->mlist, list) {
180 			printk(KERN_DEBUG
181 			       "  - member = %s (slot_tx %d, bank_tx %d, "
182 			       "slot_rx %d, bank_rx %d hfc_conf %d "
183 			       "tx_data %d rx_is_off %d)%s\n",
184 			       member->dsp->name, member->dsp->pcm_slot_tx,
185 			       member->dsp->pcm_bank_tx, member->dsp->pcm_slot_rx,
186 			       member->dsp->pcm_bank_rx, member->dsp->hfc_conf,
187 			       member->dsp->tx_data, member->dsp->rx_is_off,
188 			       (member->dsp == dsp) ? " *this*" : "");
189 		}
190 	}
191 	printk(KERN_DEBUG "-----end\n");
192 }
193 
194 /*
195  * search conference
196  */
197 static struct dsp_conf *
198 dsp_cmx_search_conf(u32 id)
199 {
200 	struct dsp_conf *conf;
201 
202 	if (!id) {
203 		printk(KERN_WARNING "%s: conference ID is 0.\n", __func__);
204 		return NULL;
205 	}
206 
207 	/* search conference */
208 	list_for_each_entry(conf, &conf_ilist, list)
209 		if (conf->id == id)
210 			return conf;
211 
212 	return NULL;
213 }
214 
215 
216 /*
217  * add member to conference
218  */
219 static int
220 dsp_cmx_add_conf_member(struct dsp *dsp, struct dsp_conf *conf)
221 {
222 	struct dsp_conf_member *member;
223 
224 	if (!conf || !dsp) {
225 		printk(KERN_WARNING "%s: conf or dsp is 0.\n", __func__);
226 		return -EINVAL;
227 	}
228 	if (dsp->member) {
229 		printk(KERN_WARNING "%s: dsp is already member in a conf.\n",
230 		       __func__);
231 		return -EINVAL;
232 	}
233 
234 	if (dsp->conf) {
235 		printk(KERN_WARNING "%s: dsp is already in a conf.\n",
236 		       __func__);
237 		return -EINVAL;
238 	}
239 
240 	member = kzalloc(sizeof(struct dsp_conf_member), GFP_ATOMIC);
241 	if (!member) {
242 		printk(KERN_ERR "kzalloc struct dsp_conf_member failed\n");
243 		return -ENOMEM;
244 	}
245 	member->dsp = dsp;
246 	/* clear rx buffer */
247 	memset(dsp->rx_buff, dsp_silence, sizeof(dsp->rx_buff));
248 	dsp->rx_init = 1; /* rx_W and rx_R will be adjusted on first frame */
249 	dsp->rx_W = 0;
250 	dsp->rx_R = 0;
251 
252 	list_add_tail(&member->list, &conf->mlist);
253 
254 	dsp->conf = conf;
255 	dsp->member = member;
256 
257 	return 0;
258 }
259 
260 
261 /*
262  * del member from conference
263  */
264 int
265 dsp_cmx_del_conf_member(struct dsp *dsp)
266 {
267 	struct dsp_conf_member *member;
268 
269 	if (!dsp) {
270 		printk(KERN_WARNING "%s: dsp is 0.\n",
271 		       __func__);
272 		return -EINVAL;
273 	}
274 
275 	if (!dsp->conf) {
276 		printk(KERN_WARNING "%s: dsp is not in a conf.\n",
277 		       __func__);
278 		return -EINVAL;
279 	}
280 
281 	if (list_empty(&dsp->conf->mlist)) {
282 		printk(KERN_WARNING "%s: dsp has linked an empty conf.\n",
283 		       __func__);
284 		return -EINVAL;
285 	}
286 
287 	/* find us in conf */
288 	list_for_each_entry(member, &dsp->conf->mlist, list) {
289 		if (member->dsp == dsp) {
290 			list_del(&member->list);
291 			dsp->conf = NULL;
292 			dsp->member = NULL;
293 			kfree(member);
294 			return 0;
295 		}
296 	}
297 	printk(KERN_WARNING
298 	       "%s: dsp is not present in its own conf_member list.\n",
299 	       __func__);
300 
301 	return -EINVAL;
302 }
303 
304 
305 /*
306  * new conference
307  */
308 static struct dsp_conf
309 *dsp_cmx_new_conf(u32 id)
310 {
311 	struct dsp_conf *conf;
312 
313 	if (!id) {
314 		printk(KERN_WARNING "%s: id is 0.\n",
315 		       __func__);
316 		return NULL;
317 	}
318 
319 	conf = kzalloc(sizeof(struct dsp_conf), GFP_ATOMIC);
320 	if (!conf) {
321 		printk(KERN_ERR "kzalloc struct dsp_conf failed\n");
322 		return NULL;
323 	}
324 	INIT_LIST_HEAD(&conf->mlist);
325 	conf->id = id;
326 
327 	list_add_tail(&conf->list, &conf_ilist);
328 
329 	return conf;
330 }
331 
332 
333 /*
334  * del conference
335  */
336 int
337 dsp_cmx_del_conf(struct dsp_conf *conf)
338 {
339 	if (!conf) {
340 		printk(KERN_WARNING "%s: conf is null.\n",
341 		       __func__);
342 		return -EINVAL;
343 	}
344 
345 	if (!list_empty(&conf->mlist)) {
346 		printk(KERN_WARNING "%s: conf not empty.\n",
347 		       __func__);
348 		return -EINVAL;
349 	}
350 	list_del(&conf->list);
351 	kfree(conf);
352 
353 	return 0;
354 }
355 
356 
357 /*
358  * send HW message to hfc card
359  */
360 static void
361 dsp_cmx_hw_message(struct dsp *dsp, u32 message, u32 param1, u32 param2,
362 		   u32 param3, u32 param4)
363 {
364 	struct mISDN_ctrl_req cq;
365 
366 	memset(&cq, 0, sizeof(cq));
367 	cq.op = message;
368 	cq.p1 = param1 | (param2 << 8);
369 	cq.p2 = param3 | (param4 << 8);
370 	if (dsp->ch.peer)
371 		dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq);
372 }
373 
374 
375 /*
376  * do hardware update and set the software/hardware flag
377  *
378  * either a conference or a dsp instance can be given
379  * if only dsp instance is given, the instance is not associated with a conf
380  * and therefore removed. if a conference is given, the dsp is expected to
381  * be member of that conference.
382  */
383 void
384 dsp_cmx_hardware(struct dsp_conf *conf, struct dsp *dsp)
385 {
386 	struct dsp_conf_member	*member, *nextm;
387 	struct dsp		*finddsp;
388 	int		memb = 0, i, ii, i1, i2;
389 	int		freeunits[8];
390 	u_char		freeslots[256];
391 	int		same_hfc = -1, same_pcm = -1, current_conf = -1,
392 		all_conf = 1, tx_data = 0;
393 
394 	/* dsp gets updated (no conf) */
395 	if (!conf) {
396 		if (!dsp)
397 			return;
398 		if (dsp_debug & DEBUG_DSP_CMX)
399 			printk(KERN_DEBUG "%s checking dsp %s\n",
400 			       __func__, dsp->name);
401 	one_member:
402 		/* remove HFC conference if enabled */
403 		if (dsp->hfc_conf >= 0) {
404 			if (dsp_debug & DEBUG_DSP_CMX)
405 				printk(KERN_DEBUG
406 				       "%s removing %s from HFC conf %d "
407 				       "because dsp is split\n", __func__,
408 				       dsp->name, dsp->hfc_conf);
409 			dsp_cmx_hw_message(dsp, MISDN_CTRL_HFC_CONF_SPLIT,
410 					   0, 0, 0, 0);
411 			dsp->hfc_conf = -1;
412 		}
413 		/* process hw echo */
414 		if (dsp->features.pcm_banks < 1)
415 			return;
416 		if (!dsp->echo.software && !dsp->echo.hardware) {
417 			/* NO ECHO: remove PCM slot if assigned */
418 			if (dsp->pcm_slot_tx >= 0 || dsp->pcm_slot_rx >= 0) {
419 				if (dsp_debug & DEBUG_DSP_CMX)
420 					printk(KERN_DEBUG "%s removing %s from"
421 					       " PCM slot %d (TX) %d (RX) because"
422 					       " dsp is split (no echo)\n",
423 					       __func__, dsp->name,
424 					       dsp->pcm_slot_tx, dsp->pcm_slot_rx);
425 				dsp_cmx_hw_message(dsp, MISDN_CTRL_HFC_PCM_DISC,
426 						   0, 0, 0, 0);
427 				dsp->pcm_slot_tx = -1;
428 				dsp->pcm_bank_tx = -1;
429 				dsp->pcm_slot_rx = -1;
430 				dsp->pcm_bank_rx = -1;
431 			}
432 			return;
433 		}
434 		/* echo is enabled, find out if we use soft or hardware */
435 		dsp->echo.software = dsp->tx_data;
436 		dsp->echo.hardware = 0;
437 		/* ECHO: already echo */
438 		if (dsp->pcm_slot_tx >= 0 && dsp->pcm_slot_rx < 0 &&
439 		    dsp->pcm_bank_tx == 2 && dsp->pcm_bank_rx == 2) {
440 			dsp->echo.hardware = 1;
441 			return;
442 		}
443 		/* ECHO: if slot already assigned */
444 		if (dsp->pcm_slot_tx >= 0) {
445 			dsp->pcm_slot_rx = dsp->pcm_slot_tx;
446 			dsp->pcm_bank_tx = 2; /* 2 means loop */
447 			dsp->pcm_bank_rx = 2;
448 			if (dsp_debug & DEBUG_DSP_CMX)
449 				printk(KERN_DEBUG
450 				       "%s refresh %s for echo using slot %d\n",
451 				       __func__, dsp->name,
452 				       dsp->pcm_slot_tx);
453 			dsp_cmx_hw_message(dsp, MISDN_CTRL_HFC_PCM_CONN,
454 					   dsp->pcm_slot_tx, 2, dsp->pcm_slot_rx, 2);
455 			dsp->echo.hardware = 1;
456 			return;
457 		}
458 		/* ECHO: find slot */
459 		dsp->pcm_slot_tx = -1;
460 		dsp->pcm_slot_rx = -1;
461 		memset(freeslots, 1, sizeof(freeslots));
462 		list_for_each_entry(finddsp, &dsp_ilist, list) {
463 			if (finddsp->features.pcm_id == dsp->features.pcm_id) {
464 				if (finddsp->pcm_slot_rx >= 0 &&
465 				    finddsp->pcm_slot_rx < sizeof(freeslots))
466 					freeslots[finddsp->pcm_slot_rx] = 0;
467 				if (finddsp->pcm_slot_tx >= 0 &&
468 				    finddsp->pcm_slot_tx < sizeof(freeslots))
469 					freeslots[finddsp->pcm_slot_tx] = 0;
470 			}
471 		}
472 		i = 0;
473 		ii = dsp->features.pcm_slots;
474 		while (i < ii) {
475 			if (freeslots[i])
476 				break;
477 			i++;
478 		}
479 		if (i == ii) {
480 			if (dsp_debug & DEBUG_DSP_CMX)
481 				printk(KERN_DEBUG
482 				       "%s no slot available for echo\n",
483 				       __func__);
484 			/* no more slots available */
485 			dsp->echo.software = 1;
486 			return;
487 		}
488 		/* assign free slot */
489 		dsp->pcm_slot_tx = i;
490 		dsp->pcm_slot_rx = i;
491 		dsp->pcm_bank_tx = 2; /* loop */
492 		dsp->pcm_bank_rx = 2;
493 		if (dsp_debug & DEBUG_DSP_CMX)
494 			printk(KERN_DEBUG
495 			       "%s assign echo for %s using slot %d\n",
496 			       __func__, dsp->name, dsp->pcm_slot_tx);
497 		dsp_cmx_hw_message(dsp, MISDN_CTRL_HFC_PCM_CONN,
498 				   dsp->pcm_slot_tx, 2, dsp->pcm_slot_rx, 2);
499 		dsp->echo.hardware = 1;
500 		return;
501 	}
502 
503 	/* conf gets updated (all members) */
504 	if (dsp_debug & DEBUG_DSP_CMX)
505 		printk(KERN_DEBUG "%s checking conference %d\n",
506 		       __func__, conf->id);
507 
508 	if (list_empty(&conf->mlist)) {
509 		printk(KERN_ERR "%s: conference without members\n",
510 		       __func__);
511 		return;
512 	}
513 	member = list_entry(conf->mlist.next, struct dsp_conf_member, list);
514 	same_hfc = member->dsp->features.hfc_id;
515 	same_pcm = member->dsp->features.pcm_id;
516 	/* check all members in our conference */
517 	list_for_each_entry(member, &conf->mlist, list) {
518 		/* check if member uses mixing */
519 		if (member->dsp->tx_mix) {
520 			if (dsp_debug & DEBUG_DSP_CMX)
521 				printk(KERN_DEBUG
522 				       "%s dsp %s cannot form a conf, because "
523 				       "tx_mix is turned on\n", __func__,
524 				       member->dsp->name);
525 		conf_software:
526 			list_for_each_entry(member, &conf->mlist, list) {
527 				dsp = member->dsp;
528 				/* remove HFC conference if enabled */
529 				if (dsp->hfc_conf >= 0) {
530 					if (dsp_debug & DEBUG_DSP_CMX)
531 						printk(KERN_DEBUG
532 						       "%s removing %s from HFC "
533 						       "conf %d because not "
534 						       "possible with hardware\n",
535 						       __func__,
536 						       dsp->name,
537 						       dsp->hfc_conf);
538 					dsp_cmx_hw_message(dsp,
539 							   MISDN_CTRL_HFC_CONF_SPLIT,
540 							   0, 0, 0, 0);
541 					dsp->hfc_conf = -1;
542 				}
543 				/* remove PCM slot if assigned */
544 				if (dsp->pcm_slot_tx >= 0 ||
545 				    dsp->pcm_slot_rx >= 0) {
546 					if (dsp_debug & DEBUG_DSP_CMX)
547 						printk(KERN_DEBUG "%s removing "
548 						       "%s from PCM slot %d (TX)"
549 						       " slot %d (RX) because not"
550 						       " possible with hardware\n",
551 						       __func__,
552 						       dsp->name,
553 						       dsp->pcm_slot_tx,
554 						       dsp->pcm_slot_rx);
555 					dsp_cmx_hw_message(dsp,
556 							   MISDN_CTRL_HFC_PCM_DISC,
557 							   0, 0, 0, 0);
558 					dsp->pcm_slot_tx = -1;
559 					dsp->pcm_bank_tx = -1;
560 					dsp->pcm_slot_rx = -1;
561 					dsp->pcm_bank_rx = -1;
562 				}
563 			}
564 			conf->hardware = 0;
565 			conf->software = 1;
566 			return;
567 		}
568 		/* check if member has echo turned on */
569 		if (member->dsp->echo.hardware || member->dsp->echo.software) {
570 			if (dsp_debug & DEBUG_DSP_CMX)
571 				printk(KERN_DEBUG
572 				       "%s dsp %s cannot form a conf, because "
573 				       "echo is turned on\n", __func__,
574 				       member->dsp->name);
575 			goto conf_software;
576 		}
577 		/* check if member has tx_mix turned on */
578 		if (member->dsp->tx_mix) {
579 			if (dsp_debug & DEBUG_DSP_CMX)
580 				printk(KERN_DEBUG
581 				       "%s dsp %s cannot form a conf, because "
582 				       "tx_mix is turned on\n",
583 				       __func__, member->dsp->name);
584 			goto conf_software;
585 		}
586 		/* check if member changes volume at an not suppoted level */
587 		if (member->dsp->tx_volume) {
588 			if (dsp_debug & DEBUG_DSP_CMX)
589 				printk(KERN_DEBUG
590 				       "%s dsp %s cannot form a conf, because "
591 				       "tx_volume is changed\n",
592 				       __func__, member->dsp->name);
593 			goto conf_software;
594 		}
595 		if (member->dsp->rx_volume) {
596 			if (dsp_debug & DEBUG_DSP_CMX)
597 				printk(KERN_DEBUG
598 				       "%s dsp %s cannot form a conf, because "
599 				       "rx_volume is changed\n",
600 				       __func__, member->dsp->name);
601 			goto conf_software;
602 		}
603 		/* check if tx-data turned on */
604 		if (member->dsp->tx_data) {
605 			if (dsp_debug & DEBUG_DSP_CMX)
606 				printk(KERN_DEBUG
607 				       "%s dsp %s tx_data is turned on\n",
608 				       __func__, member->dsp->name);
609 			tx_data = 1;
610 		}
611 		/* check if pipeline exists */
612 		if (member->dsp->pipeline.inuse) {
613 			if (dsp_debug & DEBUG_DSP_CMX)
614 				printk(KERN_DEBUG
615 				       "%s dsp %s cannot form a conf, because "
616 				       "pipeline exists\n", __func__,
617 				       member->dsp->name);
618 			goto conf_software;
619 		}
620 		/* check if encryption is enabled */
621 		if (member->dsp->bf_enable) {
622 			if (dsp_debug & DEBUG_DSP_CMX)
623 				printk(KERN_DEBUG "%s dsp %s cannot form a "
624 				       "conf, because encryption is enabled\n",
625 				       __func__, member->dsp->name);
626 			goto conf_software;
627 		}
628 		/* check if member is on a card with PCM support */
629 		if (member->dsp->features.pcm_id < 0) {
630 			if (dsp_debug & DEBUG_DSP_CMX)
631 				printk(KERN_DEBUG
632 				       "%s dsp %s cannot form a conf, because "
633 				       "dsp has no PCM bus\n",
634 				       __func__, member->dsp->name);
635 			goto conf_software;
636 		}
637 		/* check if relations are on the same PCM bus */
638 		if (member->dsp->features.pcm_id != same_pcm) {
639 			if (dsp_debug & DEBUG_DSP_CMX)
640 				printk(KERN_DEBUG
641 				       "%s dsp %s cannot form a conf, because "
642 				       "dsp is on a different PCM bus than the "
643 				       "first dsp\n",
644 				       __func__, member->dsp->name);
645 			goto conf_software;
646 		}
647 		/* determine if members are on the same hfc chip */
648 		if (same_hfc != member->dsp->features.hfc_id)
649 			same_hfc = -1;
650 		/* if there are members already in a conference */
651 		if (current_conf < 0 && member->dsp->hfc_conf >= 0)
652 			current_conf = member->dsp->hfc_conf;
653 		/* if any member is not in a conference */
654 		if (member->dsp->hfc_conf < 0)
655 			all_conf = 0;
656 
657 		memb++;
658 	}
659 
660 	/* if no member, this is an error */
661 	if (memb < 1)
662 		return;
663 
664 	/* one member */
665 	if (memb == 1) {
666 		if (dsp_debug & DEBUG_DSP_CMX)
667 			printk(KERN_DEBUG
668 			       "%s conf %d cannot form a HW conference, "
669 			       "because dsp is alone\n", __func__, conf->id);
670 		conf->hardware = 0;
671 		conf->software = 0;
672 		member = list_entry(conf->mlist.next, struct dsp_conf_member,
673 				    list);
674 		dsp = member->dsp;
675 		goto one_member;
676 	}
677 
678 	/*
679 	 * ok, now we are sure that all members are on the same pcm.
680 	 * now we will see if we have only two members, so we can do
681 	 * crossconnections, which don't have any limitations.
682 	 */
683 
684 	/* if we have only two members */
685 	if (memb == 2) {
686 		member = list_entry(conf->mlist.next, struct dsp_conf_member,
687 				    list);
688 		nextm = list_entry(member->list.next, struct dsp_conf_member,
689 				   list);
690 		/* remove HFC conference if enabled */
691 		if (member->dsp->hfc_conf >= 0) {
692 			if (dsp_debug & DEBUG_DSP_CMX)
693 				printk(KERN_DEBUG
694 				       "%s removing %s from HFC conf %d because "
695 				       "two parties require only a PCM slot\n",
696 				       __func__, member->dsp->name,
697 				       member->dsp->hfc_conf);
698 			dsp_cmx_hw_message(member->dsp,
699 					   MISDN_CTRL_HFC_CONF_SPLIT, 0, 0, 0, 0);
700 			member->dsp->hfc_conf = -1;
701 		}
702 		if (nextm->dsp->hfc_conf >= 0) {
703 			if (dsp_debug & DEBUG_DSP_CMX)
704 				printk(KERN_DEBUG
705 				       "%s removing %s from HFC conf %d because "
706 				       "two parties require only a PCM slot\n",
707 				       __func__, nextm->dsp->name,
708 				       nextm->dsp->hfc_conf);
709 			dsp_cmx_hw_message(nextm->dsp,
710 					   MISDN_CTRL_HFC_CONF_SPLIT, 0, 0, 0, 0);
711 			nextm->dsp->hfc_conf = -1;
712 		}
713 		/* if members have two banks (and not on the same chip) */
714 		if (member->dsp->features.pcm_banks > 1 &&
715 		    nextm->dsp->features.pcm_banks > 1 &&
716 		    member->dsp->features.hfc_id !=
717 		    nextm->dsp->features.hfc_id) {
718 			/* if both members have same slots with crossed banks */
719 			if (member->dsp->pcm_slot_tx >= 0 &&
720 			    member->dsp->pcm_slot_rx >= 0 &&
721 			    nextm->dsp->pcm_slot_tx >= 0 &&
722 			    nextm->dsp->pcm_slot_rx >= 0 &&
723 			    nextm->dsp->pcm_slot_tx ==
724 			    member->dsp->pcm_slot_rx &&
725 			    nextm->dsp->pcm_slot_rx ==
726 			    member->dsp->pcm_slot_tx &&
727 			    nextm->dsp->pcm_slot_tx ==
728 			    member->dsp->pcm_slot_tx &&
729 			    member->dsp->pcm_bank_tx !=
730 			    member->dsp->pcm_bank_rx &&
731 			    nextm->dsp->pcm_bank_tx !=
732 			    nextm->dsp->pcm_bank_rx) {
733 				/* all members have same slot */
734 				if (dsp_debug & DEBUG_DSP_CMX)
735 					printk(KERN_DEBUG
736 					       "%s dsp %s & %s stay joined on "
737 					       "PCM slot %d bank %d (TX) bank %d "
738 					       "(RX) (on different chips)\n",
739 					       __func__,
740 					       member->dsp->name,
741 					       nextm->dsp->name,
742 					       member->dsp->pcm_slot_tx,
743 					       member->dsp->pcm_bank_tx,
744 					       member->dsp->pcm_bank_rx);
745 				conf->hardware = 1;
746 				conf->software = tx_data;
747 				return;
748 			}
749 			/* find a new slot */
750 			memset(freeslots, 1, sizeof(freeslots));
751 			list_for_each_entry(dsp, &dsp_ilist, list) {
752 				if (dsp != member->dsp &&
753 				    dsp != nextm->dsp &&
754 				    member->dsp->features.pcm_id ==
755 				    dsp->features.pcm_id) {
756 					if (dsp->pcm_slot_rx >= 0 &&
757 					    dsp->pcm_slot_rx <
758 					    sizeof(freeslots))
759 						freeslots[dsp->pcm_slot_rx] = 0;
760 					if (dsp->pcm_slot_tx >= 0 &&
761 					    dsp->pcm_slot_tx <
762 					    sizeof(freeslots))
763 						freeslots[dsp->pcm_slot_tx] = 0;
764 				}
765 			}
766 			i = 0;
767 			ii = member->dsp->features.pcm_slots;
768 			while (i < ii) {
769 				if (freeslots[i])
770 					break;
771 				i++;
772 			}
773 			if (i == ii) {
774 				if (dsp_debug & DEBUG_DSP_CMX)
775 					printk(KERN_DEBUG
776 					       "%s no slot available for "
777 					       "%s & %s\n", __func__,
778 					       member->dsp->name,
779 					       nextm->dsp->name);
780 				/* no more slots available */
781 				goto conf_software;
782 			}
783 			/* assign free slot */
784 			member->dsp->pcm_slot_tx = i;
785 			member->dsp->pcm_slot_rx = i;
786 			nextm->dsp->pcm_slot_tx = i;
787 			nextm->dsp->pcm_slot_rx = i;
788 			member->dsp->pcm_bank_rx = 0;
789 			member->dsp->pcm_bank_tx = 1;
790 			nextm->dsp->pcm_bank_rx = 1;
791 			nextm->dsp->pcm_bank_tx = 0;
792 			if (dsp_debug & DEBUG_DSP_CMX)
793 				printk(KERN_DEBUG
794 				       "%s adding %s & %s to new PCM slot %d "
795 				       "(TX and RX on different chips) because "
796 				       "both members have not same slots\n",
797 				       __func__,
798 				       member->dsp->name,
799 				       nextm->dsp->name,
800 				       member->dsp->pcm_slot_tx);
801 			dsp_cmx_hw_message(member->dsp, MISDN_CTRL_HFC_PCM_CONN,
802 					   member->dsp->pcm_slot_tx, member->dsp->pcm_bank_tx,
803 					   member->dsp->pcm_slot_rx, member->dsp->pcm_bank_rx);
804 			dsp_cmx_hw_message(nextm->dsp, MISDN_CTRL_HFC_PCM_CONN,
805 					   nextm->dsp->pcm_slot_tx, nextm->dsp->pcm_bank_tx,
806 					   nextm->dsp->pcm_slot_rx, nextm->dsp->pcm_bank_rx);
807 			conf->hardware = 1;
808 			conf->software = tx_data;
809 			return;
810 			/* if members have one bank (or on the same chip) */
811 		} else {
812 			/* if both members have different crossed slots */
813 			if (member->dsp->pcm_slot_tx >= 0 &&
814 			    member->dsp->pcm_slot_rx >= 0 &&
815 			    nextm->dsp->pcm_slot_tx >= 0 &&
816 			    nextm->dsp->pcm_slot_rx >= 0 &&
817 			    nextm->dsp->pcm_slot_tx ==
818 			    member->dsp->pcm_slot_rx &&
819 			    nextm->dsp->pcm_slot_rx ==
820 			    member->dsp->pcm_slot_tx &&
821 			    member->dsp->pcm_slot_tx !=
822 			    member->dsp->pcm_slot_rx &&
823 			    member->dsp->pcm_bank_tx == 0 &&
824 			    member->dsp->pcm_bank_rx == 0 &&
825 			    nextm->dsp->pcm_bank_tx == 0 &&
826 			    nextm->dsp->pcm_bank_rx == 0) {
827 				/* all members have same slot */
828 				if (dsp_debug & DEBUG_DSP_CMX)
829 					printk(KERN_DEBUG
830 					       "%s dsp %s & %s stay joined on PCM "
831 					       "slot %d (TX) %d (RX) on same chip "
832 					       "or one bank PCM)\n", __func__,
833 					       member->dsp->name,
834 					       nextm->dsp->name,
835 					       member->dsp->pcm_slot_tx,
836 					       member->dsp->pcm_slot_rx);
837 				conf->hardware = 1;
838 				conf->software = tx_data;
839 				return;
840 			}
841 			/* find two new slot */
842 			memset(freeslots, 1, sizeof(freeslots));
843 			list_for_each_entry(dsp, &dsp_ilist, list) {
844 				if (dsp != member->dsp &&
845 				    dsp != nextm->dsp &&
846 				    member->dsp->features.pcm_id ==
847 				    dsp->features.pcm_id) {
848 					if (dsp->pcm_slot_rx >= 0 &&
849 					    dsp->pcm_slot_rx <
850 					    sizeof(freeslots))
851 						freeslots[dsp->pcm_slot_rx] = 0;
852 					if (dsp->pcm_slot_tx >= 0 &&
853 					    dsp->pcm_slot_tx <
854 					    sizeof(freeslots))
855 						freeslots[dsp->pcm_slot_tx] = 0;
856 				}
857 			}
858 			i1 = 0;
859 			ii = member->dsp->features.pcm_slots;
860 			while (i1 < ii) {
861 				if (freeslots[i1])
862 					break;
863 				i1++;
864 			}
865 			if (i1 == ii) {
866 				if (dsp_debug & DEBUG_DSP_CMX)
867 					printk(KERN_DEBUG
868 					       "%s no slot available "
869 					       "for %s & %s\n", __func__,
870 					       member->dsp->name,
871 					       nextm->dsp->name);
872 				/* no more slots available */
873 				goto conf_software;
874 			}
875 			i2 = i1 + 1;
876 			while (i2 < ii) {
877 				if (freeslots[i2])
878 					break;
879 				i2++;
880 			}
881 			if (i2 == ii) {
882 				if (dsp_debug & DEBUG_DSP_CMX)
883 					printk(KERN_DEBUG
884 					       "%s no slot available "
885 					       "for %s & %s\n",
886 					       __func__,
887 					       member->dsp->name,
888 					       nextm->dsp->name);
889 				/* no more slots available */
890 				goto conf_software;
891 			}
892 			/* assign free slots */
893 			member->dsp->pcm_slot_tx = i1;
894 			member->dsp->pcm_slot_rx = i2;
895 			nextm->dsp->pcm_slot_tx = i2;
896 			nextm->dsp->pcm_slot_rx = i1;
897 			member->dsp->pcm_bank_rx = 0;
898 			member->dsp->pcm_bank_tx = 0;
899 			nextm->dsp->pcm_bank_rx = 0;
900 			nextm->dsp->pcm_bank_tx = 0;
901 			if (dsp_debug & DEBUG_DSP_CMX)
902 				printk(KERN_DEBUG
903 				       "%s adding %s & %s to new PCM slot %d "
904 				       "(TX) %d (RX) on same chip or one bank "
905 				       "PCM, because both members have not "
906 				       "crossed slots\n", __func__,
907 				       member->dsp->name,
908 				       nextm->dsp->name,
909 				       member->dsp->pcm_slot_tx,
910 				       member->dsp->pcm_slot_rx);
911 			dsp_cmx_hw_message(member->dsp, MISDN_CTRL_HFC_PCM_CONN,
912 					   member->dsp->pcm_slot_tx, member->dsp->pcm_bank_tx,
913 					   member->dsp->pcm_slot_rx, member->dsp->pcm_bank_rx);
914 			dsp_cmx_hw_message(nextm->dsp, MISDN_CTRL_HFC_PCM_CONN,
915 					   nextm->dsp->pcm_slot_tx, nextm->dsp->pcm_bank_tx,
916 					   nextm->dsp->pcm_slot_rx, nextm->dsp->pcm_bank_rx);
917 			conf->hardware = 1;
918 			conf->software = tx_data;
919 			return;
920 		}
921 	}
922 
923 	/*
924 	 * if we have more than two, we may check if we have a conference
925 	 * unit available on the chip. also all members must be on the same
926 	 */
927 
928 	/* if not the same HFC chip */
929 	if (same_hfc < 0) {
930 		if (dsp_debug & DEBUG_DSP_CMX)
931 			printk(KERN_DEBUG
932 			       "%s conference %d cannot be formed, because "
933 			       "members are on different chips or not "
934 			       "on HFC chip\n",
935 			       __func__, conf->id);
936 		goto conf_software;
937 	}
938 
939 	/* for more than two members.. */
940 
941 	/* if all members already have the same conference */
942 	if (all_conf) {
943 		conf->hardware = 1;
944 		conf->software = tx_data;
945 		return;
946 	}
947 
948 	/*
949 	 * if there is an existing conference, but not all members have joined
950 	 */
951 	if (current_conf >= 0) {
952 	join_members:
953 		list_for_each_entry(member, &conf->mlist, list) {
954 			/* if no conference engine on our chip, change to
955 			 * software */
956 			if (!member->dsp->features.hfc_conf)
957 				goto conf_software;
958 			/* in case of hdlc, change to software */
959 			if (member->dsp->hdlc)
960 				goto conf_software;
961 			/* join to current conference */
962 			if (member->dsp->hfc_conf == current_conf)
963 				continue;
964 			/* get a free timeslot first */
965 			memset(freeslots, 1, sizeof(freeslots));
966 			list_for_each_entry(dsp, &dsp_ilist, list) {
967 				/*
968 				 * not checking current member, because
969 				 * slot will be overwritten.
970 				 */
971 				if (
972 					dsp != member->dsp &&
973 					/* dsp must be on the same PCM */
974 					member->dsp->features.pcm_id ==
975 					dsp->features.pcm_id) {
976 					/* dsp must be on a slot */
977 					if (dsp->pcm_slot_tx >= 0 &&
978 					    dsp->pcm_slot_tx <
979 					    sizeof(freeslots))
980 						freeslots[dsp->pcm_slot_tx] = 0;
981 					if (dsp->pcm_slot_rx >= 0 &&
982 					    dsp->pcm_slot_rx <
983 					    sizeof(freeslots))
984 						freeslots[dsp->pcm_slot_rx] = 0;
985 				}
986 			}
987 			i = 0;
988 			ii = member->dsp->features.pcm_slots;
989 			while (i < ii) {
990 				if (freeslots[i])
991 					break;
992 				i++;
993 			}
994 			if (i == ii) {
995 				/* no more slots available */
996 				if (dsp_debug & DEBUG_DSP_CMX)
997 					printk(KERN_DEBUG
998 					       "%s conference %d cannot be formed,"
999 					       " because no slot free\n",
1000 					       __func__, conf->id);
1001 				goto conf_software;
1002 			}
1003 			if (dsp_debug & DEBUG_DSP_CMX)
1004 				printk(KERN_DEBUG
1005 				       "%s changing dsp %s to HW conference "
1006 				       "%d slot %d\n", __func__,
1007 				       member->dsp->name, current_conf, i);
1008 			/* assign free slot & set PCM & join conf */
1009 			member->dsp->pcm_slot_tx = i;
1010 			member->dsp->pcm_slot_rx = i;
1011 			member->dsp->pcm_bank_tx = 2; /* loop */
1012 			member->dsp->pcm_bank_rx = 2;
1013 			member->dsp->hfc_conf = current_conf;
1014 			dsp_cmx_hw_message(member->dsp, MISDN_CTRL_HFC_PCM_CONN,
1015 					   i, 2, i, 2);
1016 			dsp_cmx_hw_message(member->dsp,
1017 					   MISDN_CTRL_HFC_CONF_JOIN, current_conf, 0, 0, 0);
1018 		}
1019 		conf->hardware = 1;
1020 		conf->software = tx_data;
1021 		return;
1022 	}
1023 
1024 	/*
1025 	 * no member is in a conference yet, so we find a free one
1026 	 */
1027 	memset(freeunits, 1, sizeof(freeunits));
1028 	list_for_each_entry(dsp, &dsp_ilist, list) {
1029 		/* dsp must be on the same chip */
1030 		if (dsp->features.hfc_id == same_hfc &&
1031 		    /* dsp must have joined a HW conference */
1032 		    dsp->hfc_conf >= 0 &&
1033 		    /* slot must be within range */
1034 		    dsp->hfc_conf < 8)
1035 			freeunits[dsp->hfc_conf] = 0;
1036 	}
1037 	i = 0;
1038 	ii = 8;
1039 	while (i < ii) {
1040 		if (freeunits[i])
1041 			break;
1042 		i++;
1043 	}
1044 	if (i == ii) {
1045 		/* no more conferences available */
1046 		if (dsp_debug & DEBUG_DSP_CMX)
1047 			printk(KERN_DEBUG
1048 			       "%s conference %d cannot be formed, because "
1049 			       "no conference number free\n",
1050 			       __func__, conf->id);
1051 		goto conf_software;
1052 	}
1053 	/* join all members */
1054 	current_conf = i;
1055 	goto join_members;
1056 }
1057 
1058 
1059 /*
1060  * conf_id != 0: join or change conference
1061  * conf_id == 0: split from conference if not already
1062  */
1063 int
1064 dsp_cmx_conf(struct dsp *dsp, u32 conf_id)
1065 {
1066 	int err;
1067 	struct dsp_conf *conf;
1068 	struct dsp_conf_member	*member;
1069 
1070 	/* if conference doesn't change */
1071 	if (dsp->conf_id == conf_id)
1072 		return 0;
1073 
1074 	/* first remove us from current conf */
1075 	if (dsp->conf_id) {
1076 		if (dsp_debug & DEBUG_DSP_CMX)
1077 			printk(KERN_DEBUG "removing us from conference %d\n",
1078 			       dsp->conf->id);
1079 		/* remove us from conf */
1080 		conf = dsp->conf;
1081 		err = dsp_cmx_del_conf_member(dsp);
1082 		if (err)
1083 			return err;
1084 		dsp->conf_id = 0;
1085 
1086 		/* update hardware */
1087 		dsp_cmx_hardware(NULL, dsp);
1088 
1089 		/* conf now empty? */
1090 		if (list_empty(&conf->mlist)) {
1091 			if (dsp_debug & DEBUG_DSP_CMX)
1092 				printk(KERN_DEBUG
1093 				       "conference is empty, so we remove it.\n");
1094 			err = dsp_cmx_del_conf(conf);
1095 			if (err)
1096 				return err;
1097 		} else {
1098 			/* update members left on conf */
1099 			dsp_cmx_hardware(conf, NULL);
1100 		}
1101 	}
1102 
1103 	/* if split */
1104 	if (!conf_id)
1105 		return 0;
1106 
1107 	/* now add us to conf */
1108 	if (dsp_debug & DEBUG_DSP_CMX)
1109 		printk(KERN_DEBUG "searching conference %d\n",
1110 		       conf_id);
1111 	conf = dsp_cmx_search_conf(conf_id);
1112 	if (!conf) {
1113 		if (dsp_debug & DEBUG_DSP_CMX)
1114 			printk(KERN_DEBUG
1115 			       "conference doesn't exist yet, creating.\n");
1116 		/* the conference doesn't exist, so we create */
1117 		conf = dsp_cmx_new_conf(conf_id);
1118 		if (!conf)
1119 			return -EINVAL;
1120 	} else if (!list_empty(&conf->mlist)) {
1121 		member = list_entry(conf->mlist.next, struct dsp_conf_member,
1122 				    list);
1123 		if (dsp->hdlc && !member->dsp->hdlc) {
1124 			if (dsp_debug & DEBUG_DSP_CMX)
1125 				printk(KERN_DEBUG
1126 				       "cannot join transparent conference.\n");
1127 			return -EINVAL;
1128 		}
1129 		if (!dsp->hdlc && member->dsp->hdlc) {
1130 			if (dsp_debug & DEBUG_DSP_CMX)
1131 				printk(KERN_DEBUG
1132 				       "cannot join hdlc conference.\n");
1133 			return -EINVAL;
1134 		}
1135 	}
1136 	/* add conference member */
1137 	err = dsp_cmx_add_conf_member(dsp, conf);
1138 	if (err)
1139 		return err;
1140 	dsp->conf_id = conf_id;
1141 
1142 	/* if we are alone, we do nothing! */
1143 	if (list_empty(&conf->mlist)) {
1144 		if (dsp_debug & DEBUG_DSP_CMX)
1145 			printk(KERN_DEBUG
1146 			       "we are alone in this conference, so exit.\n");
1147 		/* update hardware */
1148 		dsp_cmx_hardware(NULL, dsp);
1149 		return 0;
1150 	}
1151 
1152 	/* update members on conf */
1153 	dsp_cmx_hardware(conf, NULL);
1154 
1155 	return 0;
1156 }
1157 
1158 #ifdef CMX_DELAY_DEBUG
1159 int delaycount;
1160 static void
1161 showdelay(struct dsp *dsp, int samples, int delay)
1162 {
1163 	char bar[] = "--------------------------------------------------|";
1164 	int sdelay;
1165 
1166 	delaycount += samples;
1167 	if (delaycount < 8000)
1168 		return;
1169 	delaycount = 0;
1170 
1171 	sdelay = delay * 50 / (dsp_poll << 2);
1172 
1173 	printk(KERN_DEBUG "DELAY (%s) %3d >%s\n", dsp->name, delay,
1174 	       sdelay > 50 ? "..." : bar + 50 - sdelay);
1175 }
1176 #endif
1177 
1178 /*
1179  * audio data is received from card
1180  */
1181 void
1182 dsp_cmx_receive(struct dsp *dsp, struct sk_buff *skb)
1183 {
1184 	u8 *d, *p;
1185 	int len = skb->len;
1186 	struct mISDNhead *hh = mISDN_HEAD_P(skb);
1187 	int w, i, ii;
1188 
1189 	/* check if we have sompen */
1190 	if (len < 1)
1191 		return;
1192 
1193 	/* half of the buffer should be larger than maximum packet size */
1194 	if (len >= CMX_BUFF_HALF) {
1195 		printk(KERN_ERR
1196 		       "%s line %d: packet from card is too large (%d bytes). "
1197 		       "please make card send smaller packets OR increase "
1198 		       "CMX_BUFF_SIZE\n", __FILE__, __LINE__, len);
1199 		return;
1200 	}
1201 
1202 	/*
1203 	 * initialize pointers if not already -
1204 	 * also add delay if requested by PH_SIGNAL
1205 	 */
1206 	if (dsp->rx_init) {
1207 		dsp->rx_init = 0;
1208 		if (dsp->features.unordered) {
1209 			dsp->rx_R = (hh->id & CMX_BUFF_MASK);
1210 			if (dsp->cmx_delay)
1211 				dsp->rx_W = (dsp->rx_R + dsp->cmx_delay)
1212 					& CMX_BUFF_MASK;
1213 			else
1214 				dsp->rx_W = (dsp->rx_R + (dsp_poll >> 1))
1215 					& CMX_BUFF_MASK;
1216 		} else {
1217 			dsp->rx_R = 0;
1218 			if (dsp->cmx_delay)
1219 				dsp->rx_W = dsp->cmx_delay;
1220 			else
1221 				dsp->rx_W = dsp_poll >> 1;
1222 		}
1223 	}
1224 	/* if frame contains time code, write directly */
1225 	if (dsp->features.unordered) {
1226 		dsp->rx_W = (hh->id & CMX_BUFF_MASK);
1227 		/* printk(KERN_DEBUG "%s %08x\n", dsp->name, hh->id); */
1228 	}
1229 	/*
1230 	 * if we underrun (or maybe overrun),
1231 	 * we set our new read pointer, and write silence to buffer
1232 	 */
1233 	if (((dsp->rx_W-dsp->rx_R) & CMX_BUFF_MASK) >= CMX_BUFF_HALF) {
1234 		if (dsp_debug & DEBUG_DSP_CLOCK)
1235 			printk(KERN_DEBUG
1236 			       "cmx_receive(dsp=%lx): UNDERRUN (or overrun the "
1237 			       "maximum delay), adjusting read pointer! "
1238 			       "(inst %s)\n", (u_long)dsp, dsp->name);
1239 		/* flush rx buffer and set delay to dsp_poll / 2 */
1240 		if (dsp->features.unordered) {
1241 			dsp->rx_R = (hh->id & CMX_BUFF_MASK);
1242 			if (dsp->cmx_delay)
1243 				dsp->rx_W = (dsp->rx_R + dsp->cmx_delay)
1244 					& CMX_BUFF_MASK;
1245 			else
1246 				dsp->rx_W = (dsp->rx_R + (dsp_poll >> 1))
1247 					& CMX_BUFF_MASK;
1248 		} else {
1249 			dsp->rx_R = 0;
1250 			if (dsp->cmx_delay)
1251 				dsp->rx_W = dsp->cmx_delay;
1252 			else
1253 				dsp->rx_W = dsp_poll >> 1;
1254 		}
1255 		memset(dsp->rx_buff, dsp_silence, sizeof(dsp->rx_buff));
1256 	}
1257 	/* if we have reached double delay, jump back to middle */
1258 	if (dsp->cmx_delay)
1259 		if (((dsp->rx_W - dsp->rx_R) & CMX_BUFF_MASK) >=
1260 		    (dsp->cmx_delay << 1)) {
1261 			if (dsp_debug & DEBUG_DSP_CLOCK)
1262 				printk(KERN_DEBUG
1263 				       "cmx_receive(dsp=%lx): OVERRUN (because "
1264 				       "twice the delay is reached), adjusting "
1265 				       "read pointer! (inst %s)\n",
1266 				       (u_long)dsp, dsp->name);
1267 			/* flush buffer */
1268 			if (dsp->features.unordered) {
1269 				dsp->rx_R = (hh->id & CMX_BUFF_MASK);
1270 				dsp->rx_W = (dsp->rx_R + dsp->cmx_delay)
1271 					& CMX_BUFF_MASK;
1272 			} else {
1273 				dsp->rx_R = 0;
1274 				dsp->rx_W = dsp->cmx_delay;
1275 			}
1276 			memset(dsp->rx_buff, dsp_silence, sizeof(dsp->rx_buff));
1277 		}
1278 
1279 	/* show where to write */
1280 #ifdef CMX_DEBUG
1281 	printk(KERN_DEBUG
1282 	       "cmx_receive(dsp=%lx): rx_R(dsp)=%05x rx_W(dsp)=%05x len=%d %s\n",
1283 	       (u_long)dsp, dsp->rx_R, dsp->rx_W, len, dsp->name);
1284 #endif
1285 
1286 	/* write data into rx_buffer */
1287 	p = skb->data;
1288 	d = dsp->rx_buff;
1289 	w = dsp->rx_W;
1290 	i = 0;
1291 	ii = len;
1292 	while (i < ii) {
1293 		d[w++ & CMX_BUFF_MASK] = *p++;
1294 		i++;
1295 	}
1296 
1297 	/* increase write-pointer */
1298 	dsp->rx_W = ((dsp->rx_W + len) & CMX_BUFF_MASK);
1299 #ifdef CMX_DELAY_DEBUG
1300 	showdelay(dsp, len, (dsp->rx_W-dsp->rx_R) & CMX_BUFF_MASK);
1301 #endif
1302 }
1303 
1304 
1305 /*
1306  * send (mixed) audio data to card and control jitter
1307  */
1308 static void
1309 dsp_cmx_send_member(struct dsp *dsp, int len, s32 *c, int members)
1310 {
1311 	struct dsp_conf *conf = dsp->conf;
1312 	struct dsp *member, *other;
1313 	register s32 sample;
1314 	u8 *d, *p, *q, *o_q;
1315 	struct sk_buff *nskb, *txskb;
1316 	int r, rr, t, tt, o_r, o_rr;
1317 	int preload = 0;
1318 	struct mISDNhead *hh, *thh;
1319 	int tx_data_only = 0;
1320 
1321 	/* don't process if: */
1322 	if (!dsp->b_active) { /* if not active */
1323 		dsp->last_tx = 0;
1324 		return;
1325 	}
1326 	if (((dsp->conf && dsp->conf->hardware) || /* hardware conf */
1327 	     dsp->echo.hardware) && /* OR hardware echo */
1328 	    dsp->tx_R == dsp->tx_W && /* AND no tx-data */
1329 	    !(dsp->tone.tone && dsp->tone.software)) { /* AND not soft tones */
1330 		if (!dsp->tx_data) { /* no tx_data for user space required */
1331 			dsp->last_tx = 0;
1332 			return;
1333 		}
1334 		if (dsp->conf && dsp->conf->software && dsp->conf->hardware)
1335 			tx_data_only = 1;
1336 		if (dsp->echo.software && dsp->echo.hardware)
1337 			tx_data_only = 1;
1338 	}
1339 
1340 #ifdef CMX_DEBUG
1341 	printk(KERN_DEBUG
1342 	       "SEND members=%d dsp=%s, conf=%p, rx_R=%05x rx_W=%05x\n",
1343 	       members, dsp->name, conf, dsp->rx_R, dsp->rx_W);
1344 #endif
1345 
1346 	/* preload if we have delay set */
1347 	if (dsp->cmx_delay && !dsp->last_tx) {
1348 		preload = len;
1349 		if (preload < 128)
1350 			preload = 128;
1351 	}
1352 
1353 	/* PREPARE RESULT */
1354 	nskb = mI_alloc_skb(len + preload, GFP_ATOMIC);
1355 	if (!nskb) {
1356 		printk(KERN_ERR
1357 		       "FATAL ERROR in mISDN_dsp.o: cannot alloc %d bytes\n",
1358 		       len + preload);
1359 		return;
1360 	}
1361 	hh = mISDN_HEAD_P(nskb);
1362 	hh->prim = PH_DATA_REQ;
1363 	hh->id = 0;
1364 	dsp->last_tx = 1;
1365 
1366 	/* set pointers, indexes and stuff */
1367 	member = dsp;
1368 	p = dsp->tx_buff; /* transmit data */
1369 	q = dsp->rx_buff; /* received data */
1370 	d = skb_put(nskb, preload + len); /* result */
1371 	t = dsp->tx_R; /* tx-pointers */
1372 	tt = dsp->tx_W;
1373 	r = dsp->rx_R; /* rx-pointers */
1374 	rr = (r + len) & CMX_BUFF_MASK;
1375 
1376 	/* preload with silence, if required */
1377 	if (preload) {
1378 		memset(d, dsp_silence, preload);
1379 		d += preload;
1380 	}
1381 
1382 	/* PROCESS TONES/TX-DATA ONLY */
1383 	if (dsp->tone.tone && dsp->tone.software) {
1384 		/* -> copy tone */
1385 		dsp_tone_copy(dsp, d, len);
1386 		dsp->tx_R = 0; /* clear tx buffer */
1387 		dsp->tx_W = 0;
1388 		goto send_packet;
1389 	}
1390 	/* if we have tx-data but do not use mixing */
1391 	if (!dsp->tx_mix && t != tt) {
1392 		/* -> send tx-data and continue when not enough */
1393 #ifdef CMX_TX_DEBUG
1394 		sprintf(debugbuf, "TX sending (%04x-%04x)%p: ", t, tt, p);
1395 #endif
1396 		while (r != rr && t != tt) {
1397 #ifdef CMX_TX_DEBUG
1398 			if (strlen(debugbuf) < 48)
1399 				sprintf(debugbuf + strlen(debugbuf), " %02x",
1400 					p[t]);
1401 #endif
1402 			*d++ = p[t]; /* write tx_buff */
1403 			t = (t + 1) & CMX_BUFF_MASK;
1404 			r = (r + 1) & CMX_BUFF_MASK;
1405 		}
1406 		if (r == rr) {
1407 			dsp->tx_R = t;
1408 #ifdef CMX_TX_DEBUG
1409 			printk(KERN_DEBUG "%s\n", debugbuf);
1410 #endif
1411 			goto send_packet;
1412 		}
1413 	}
1414 #ifdef CMX_TX_DEBUG
1415 	printk(KERN_DEBUG "%s\n", debugbuf);
1416 #endif
1417 
1418 	/* PROCESS DATA (one member / no conf) */
1419 	if (!conf || members <= 1) {
1420 		/* -> if echo is NOT enabled */
1421 		if (!dsp->echo.software) {
1422 			/* -> send tx-data if available or use 0-volume */
1423 			while (r != rr && t != tt) {
1424 				*d++ = p[t]; /* write tx_buff */
1425 				t = (t + 1) & CMX_BUFF_MASK;
1426 				r = (r + 1) & CMX_BUFF_MASK;
1427 			}
1428 			if (r != rr) {
1429 				if (dsp_debug & DEBUG_DSP_CLOCK)
1430 					printk(KERN_DEBUG "%s: RX empty\n",
1431 					       __func__);
1432 				memset(d, dsp_silence, (rr - r) & CMX_BUFF_MASK);
1433 			}
1434 			/* -> if echo is enabled */
1435 		} else {
1436 			/*
1437 			 * -> mix tx-data with echo if available,
1438 			 * or use echo only
1439 			 */
1440 			while (r != rr && t != tt) {
1441 				*d++ = dsp_audio_mix_law[(p[t] << 8) | q[r]];
1442 				t = (t + 1) & CMX_BUFF_MASK;
1443 				r = (r + 1) & CMX_BUFF_MASK;
1444 			}
1445 			while (r != rr) {
1446 				*d++ = q[r]; /* echo */
1447 				r = (r + 1) & CMX_BUFF_MASK;
1448 			}
1449 		}
1450 		dsp->tx_R = t;
1451 		goto send_packet;
1452 	}
1453 	/* PROCESS DATA (two members) */
1454 #ifdef CMX_CONF_DEBUG
1455 	if (0) {
1456 #else
1457 	if (members == 2) {
1458 #endif
1459 		/* "other" becomes other party */
1460 		other = (list_entry(conf->mlist.next,
1461 				    struct dsp_conf_member, list))->dsp;
1462 		if (other == member)
1463 			other = (list_entry(conf->mlist.prev,
1464 				    struct dsp_conf_member, list))->dsp;
1465 		o_q = other->rx_buff; /* received data */
1466 		o_rr = (other->rx_R + len) & CMX_BUFF_MASK;
1467 		/* end of rx-pointer */
1468 		o_r = (o_rr - rr + r) & CMX_BUFF_MASK;
1469 		/* start rx-pointer at current read position*/
1470 		/* -> if echo is NOT enabled */
1471 		if (!dsp->echo.software) {
1472 			/*
1473 			 * -> copy other member's rx-data,
1474 			 * if tx-data is available, mix
1475 			 */
1476 			while (o_r != o_rr && t != tt) {
1477 				*d++ = dsp_audio_mix_law[(p[t] << 8) | o_q[o_r]];
1478 				t = (t + 1) & CMX_BUFF_MASK;
1479 				o_r = (o_r + 1) & CMX_BUFF_MASK;
1480 			}
1481 			while (o_r != o_rr) {
1482 				*d++ = o_q[o_r];
1483 				o_r = (o_r + 1) & CMX_BUFF_MASK;
1484 			}
1485 			/* -> if echo is enabled */
1486 		} else {
1487 			/*
1488 			 * -> mix other member's rx-data with echo,
1489 			 * if tx-data is available, mix
1490 			 */
1491 			while (r != rr && t != tt) {
1492 				sample = dsp_audio_law_to_s32[p[t]] +
1493 					dsp_audio_law_to_s32[q[r]] +
1494 					dsp_audio_law_to_s32[o_q[o_r]];
1495 				if (sample < -32768)
1496 					sample = -32768;
1497 				else if (sample > 32767)
1498 					sample = 32767;
1499 				*d++ = dsp_audio_s16_to_law[sample & 0xffff];
1500 				/* tx-data + rx_data + echo */
1501 				t = (t + 1) & CMX_BUFF_MASK;
1502 				r = (r + 1) & CMX_BUFF_MASK;
1503 				o_r = (o_r + 1) & CMX_BUFF_MASK;
1504 			}
1505 			while (r != rr) {
1506 				*d++ = dsp_audio_mix_law[(q[r] << 8) | o_q[o_r]];
1507 				r = (r + 1) & CMX_BUFF_MASK;
1508 				o_r = (o_r + 1) & CMX_BUFF_MASK;
1509 			}
1510 		}
1511 		dsp->tx_R = t;
1512 		goto send_packet;
1513 	}
1514 	/* PROCESS DATA (three or more members) */
1515 	/* -> if echo is NOT enabled */
1516 	if (!dsp->echo.software) {
1517 		/*
1518 		 * -> subtract rx-data from conf-data,
1519 		 * if tx-data is available, mix
1520 		 */
1521 		while (r != rr && t != tt) {
1522 			sample = dsp_audio_law_to_s32[p[t]] + *c++ -
1523 				dsp_audio_law_to_s32[q[r]];
1524 			if (sample < -32768)
1525 				sample = -32768;
1526 			else if (sample > 32767)
1527 				sample = 32767;
1528 			*d++ = dsp_audio_s16_to_law[sample & 0xffff];
1529 			/* conf-rx+tx */
1530 			r = (r + 1) & CMX_BUFF_MASK;
1531 			t = (t + 1) & CMX_BUFF_MASK;
1532 		}
1533 		while (r != rr) {
1534 			sample = *c++ - dsp_audio_law_to_s32[q[r]];
1535 			if (sample < -32768)
1536 				sample = -32768;
1537 			else if (sample > 32767)
1538 				sample = 32767;
1539 			*d++ = dsp_audio_s16_to_law[sample & 0xffff];
1540 			/* conf-rx */
1541 			r = (r + 1) & CMX_BUFF_MASK;
1542 		}
1543 		/* -> if echo is enabled */
1544 	} else {
1545 		/*
1546 		 * -> encode conf-data, if tx-data
1547 		 * is available, mix
1548 		 */
1549 		while (r != rr && t != tt) {
1550 			sample = dsp_audio_law_to_s32[p[t]] + *c++;
1551 			if (sample < -32768)
1552 				sample = -32768;
1553 			else if (sample > 32767)
1554 				sample = 32767;
1555 			*d++ = dsp_audio_s16_to_law[sample & 0xffff];
1556 			/* conf(echo)+tx */
1557 			t = (t + 1) & CMX_BUFF_MASK;
1558 			r = (r + 1) & CMX_BUFF_MASK;
1559 		}
1560 		while (r != rr) {
1561 			sample = *c++;
1562 			if (sample < -32768)
1563 				sample = -32768;
1564 			else if (sample > 32767)
1565 				sample = 32767;
1566 			*d++ = dsp_audio_s16_to_law[sample & 0xffff];
1567 			/* conf(echo) */
1568 			r = (r + 1) & CMX_BUFF_MASK;
1569 		}
1570 	}
1571 	dsp->tx_R = t;
1572 	goto send_packet;
1573 
1574 send_packet:
1575 	/*
1576 	 * send tx-data if enabled - don't filter,
1577 	 * because we want what we send, not what we filtered
1578 	 */
1579 	if (dsp->tx_data) {
1580 		if (tx_data_only) {
1581 			hh->prim = DL_DATA_REQ;
1582 			hh->id = 0;
1583 			/* queue and trigger */
1584 			skb_queue_tail(&dsp->sendq, nskb);
1585 			schedule_work(&dsp->workq);
1586 			/* exit because only tx_data is used */
1587 			return;
1588 		} else {
1589 			txskb = mI_alloc_skb(len, GFP_ATOMIC);
1590 			if (!txskb) {
1591 				printk(KERN_ERR
1592 				       "FATAL ERROR in mISDN_dsp.o: "
1593 				       "cannot alloc %d bytes\n", len);
1594 			} else {
1595 				thh = mISDN_HEAD_P(txskb);
1596 				thh->prim = DL_DATA_REQ;
1597 				thh->id = 0;
1598 				skb_put_data(txskb, nskb->data + preload, len);
1599 				/* queue (trigger later) */
1600 				skb_queue_tail(&dsp->sendq, txskb);
1601 			}
1602 		}
1603 	}
1604 
1605 	/* send data only to card, if we don't just calculated tx_data */
1606 	/* adjust volume */
1607 	if (dsp->tx_volume)
1608 		dsp_change_volume(nskb, dsp->tx_volume);
1609 	/* pipeline */
1610 	if (dsp->pipeline.inuse)
1611 		dsp_pipeline_process_tx(&dsp->pipeline, nskb->data,
1612 					nskb->len);
1613 	/* crypt */
1614 	if (dsp->bf_enable)
1615 		dsp_bf_encrypt(dsp, nskb->data, nskb->len);
1616 	/* queue and trigger */
1617 	skb_queue_tail(&dsp->sendq, nskb);
1618 	schedule_work(&dsp->workq);
1619 }
1620 
1621 static u32	jittercount; /* counter for jitter check */
1622 struct timer_list dsp_spl_tl;
1623 unsigned long	dsp_spl_jiffies; /* calculate the next time to fire */
1624 static u16	dsp_count; /* last sample count */
1625 static int	dsp_count_valid; /* if we have last sample count */
1626 
1627 void
1628 dsp_cmx_send(void *arg)
1629 {
1630 	struct dsp_conf *conf;
1631 	struct dsp_conf_member *member;
1632 	struct dsp *dsp;
1633 	int mustmix, members;
1634 	static s32 mixbuffer[MAX_POLL + 100];
1635 	s32 *c;
1636 	u8 *p, *q;
1637 	int r, rr;
1638 	int jittercheck = 0, delay, i;
1639 	u_long flags;
1640 	u16 length, count;
1641 
1642 	/* lock */
1643 	spin_lock_irqsave(&dsp_lock, flags);
1644 
1645 	if (!dsp_count_valid) {
1646 		dsp_count = mISDN_clock_get();
1647 		length = dsp_poll;
1648 		dsp_count_valid = 1;
1649 	} else {
1650 		count = mISDN_clock_get();
1651 		length = count - dsp_count;
1652 		dsp_count = count;
1653 	}
1654 	if (length > MAX_POLL + 100)
1655 		length = MAX_POLL + 100;
1656 	/* printk(KERN_DEBUG "len=%d dsp_count=0x%x\n", length, dsp_count); */
1657 
1658 	/*
1659 	 * check if jitter needs to be checked (this is every second)
1660 	 */
1661 	jittercount += length;
1662 	if (jittercount >= 8000) {
1663 		jittercount -= 8000;
1664 		jittercheck = 1;
1665 	}
1666 
1667 	/* loop all members that do not require conference mixing */
1668 	list_for_each_entry(dsp, &dsp_ilist, list) {
1669 		if (dsp->hdlc)
1670 			continue;
1671 		conf = dsp->conf;
1672 		mustmix = 0;
1673 		members = 0;
1674 		if (conf) {
1675 			members = count_list_member(&conf->mlist);
1676 #ifdef CMX_CONF_DEBUG
1677 			if (conf->software && members > 1)
1678 #else
1679 			if (conf->software && members > 2)
1680 #endif
1681 				mustmix = 1;
1682 		}
1683 
1684 		/* transmission required */
1685 		if (!mustmix) {
1686 			dsp_cmx_send_member(dsp, length, mixbuffer, members);
1687 
1688 			/*
1689 			 * unused mixbuffer is given to prevent a
1690 			 * potential null-pointer-bug
1691 			 */
1692 		}
1693 	}
1694 
1695 	/* loop all members that require conference mixing */
1696 	list_for_each_entry(conf, &conf_ilist, list) {
1697 		/* count members and check hardware */
1698 		members = count_list_member(&conf->mlist);
1699 #ifdef CMX_CONF_DEBUG
1700 		if (conf->software && members > 1) {
1701 #else
1702 		if (conf->software && members > 2) {
1703 #endif
1704 			/* check for hdlc conf */
1705 			member = list_entry(conf->mlist.next,
1706 					    struct dsp_conf_member, list);
1707 			if (member->dsp->hdlc)
1708 				continue;
1709 			/* mix all data */
1710 			memset(mixbuffer, 0, length * sizeof(s32));
1711 			list_for_each_entry(member, &conf->mlist, list) {
1712 				dsp = member->dsp;
1713 				/* get range of data to mix */
1714 				c = mixbuffer;
1715 				q = dsp->rx_buff;
1716 				r = dsp->rx_R;
1717 				rr = (r + length) & CMX_BUFF_MASK;
1718 				/* add member's data */
1719 				while (r != rr) {
1720 					*c++ += dsp_audio_law_to_s32[q[r]];
1721 					r = (r + 1) & CMX_BUFF_MASK;
1722 				}
1723 			}
1724 
1725 			/* process each member */
1726 			list_for_each_entry(member, &conf->mlist, list) {
1727 				/* transmission */
1728 				dsp_cmx_send_member(member->dsp, length,
1729 						    mixbuffer, members);
1730 			}
1731 		}
1732 	}
1733 
1734 	/* delete rx-data, increment buffers, change pointers */
1735 	list_for_each_entry(dsp, &dsp_ilist, list) {
1736 		if (dsp->hdlc)
1737 			continue;
1738 		p = dsp->rx_buff;
1739 		q = dsp->tx_buff;
1740 		r = dsp->rx_R;
1741 		/* move receive pointer when receiving */
1742 		if (!dsp->rx_is_off) {
1743 			rr = (r + length) & CMX_BUFF_MASK;
1744 			/* delete rx-data */
1745 			while (r != rr) {
1746 				p[r] = dsp_silence;
1747 				r = (r + 1) & CMX_BUFF_MASK;
1748 			}
1749 			/* increment rx-buffer pointer */
1750 			dsp->rx_R = r; /* write incremented read pointer */
1751 		}
1752 
1753 		/* check current rx_delay */
1754 		delay = (dsp->rx_W-dsp->rx_R) & CMX_BUFF_MASK;
1755 		if (delay >= CMX_BUFF_HALF)
1756 			delay = 0; /* will be the delay before next write */
1757 		/* check for lower delay */
1758 		if (delay < dsp->rx_delay[0])
1759 			dsp->rx_delay[0] = delay;
1760 		/* check current tx_delay */
1761 		delay = (dsp->tx_W-dsp->tx_R) & CMX_BUFF_MASK;
1762 		if (delay >= CMX_BUFF_HALF)
1763 			delay = 0; /* will be the delay before next write */
1764 		/* check for lower delay */
1765 		if (delay < dsp->tx_delay[0])
1766 			dsp->tx_delay[0] = delay;
1767 		if (jittercheck) {
1768 			/* find the lowest of all rx_delays */
1769 			delay = dsp->rx_delay[0];
1770 			i = 1;
1771 			while (i < MAX_SECONDS_JITTER_CHECK) {
1772 				if (delay > dsp->rx_delay[i])
1773 					delay = dsp->rx_delay[i];
1774 				i++;
1775 			}
1776 			/*
1777 			 * remove rx_delay only if we have delay AND we
1778 			 * have not preset cmx_delay AND
1779 			 * the delay is greater dsp_poll
1780 			 */
1781 			if (delay > dsp_poll && !dsp->cmx_delay) {
1782 				if (dsp_debug & DEBUG_DSP_CLOCK)
1783 					printk(KERN_DEBUG
1784 					       "%s lowest rx_delay of %d bytes for"
1785 					       " dsp %s are now removed.\n",
1786 					       __func__, delay,
1787 					       dsp->name);
1788 				r = dsp->rx_R;
1789 				rr = (r + delay - (dsp_poll >> 1))
1790 					& CMX_BUFF_MASK;
1791 				/* delete rx-data */
1792 				while (r != rr) {
1793 					p[r] = dsp_silence;
1794 					r = (r + 1) & CMX_BUFF_MASK;
1795 				}
1796 				/* increment rx-buffer pointer */
1797 				dsp->rx_R = r;
1798 				/* write incremented read pointer */
1799 			}
1800 			/* find the lowest of all tx_delays */
1801 			delay = dsp->tx_delay[0];
1802 			i = 1;
1803 			while (i < MAX_SECONDS_JITTER_CHECK) {
1804 				if (delay > dsp->tx_delay[i])
1805 					delay = dsp->tx_delay[i];
1806 				i++;
1807 			}
1808 			/*
1809 			 * remove delay only if we have delay AND we
1810 			 * have enabled tx_dejitter
1811 			 */
1812 			if (delay > dsp_poll && dsp->tx_dejitter) {
1813 				if (dsp_debug & DEBUG_DSP_CLOCK)
1814 					printk(KERN_DEBUG
1815 					       "%s lowest tx_delay of %d bytes for"
1816 					       " dsp %s are now removed.\n",
1817 					       __func__, delay,
1818 					       dsp->name);
1819 				r = dsp->tx_R;
1820 				rr = (r + delay - (dsp_poll >> 1))
1821 					& CMX_BUFF_MASK;
1822 				/* delete tx-data */
1823 				while (r != rr) {
1824 					q[r] = dsp_silence;
1825 					r = (r + 1) & CMX_BUFF_MASK;
1826 				}
1827 				/* increment rx-buffer pointer */
1828 				dsp->tx_R = r;
1829 				/* write incremented read pointer */
1830 			}
1831 			/* scroll up delays */
1832 			i = MAX_SECONDS_JITTER_CHECK - 1;
1833 			while (i) {
1834 				dsp->rx_delay[i] = dsp->rx_delay[i - 1];
1835 				dsp->tx_delay[i] = dsp->tx_delay[i - 1];
1836 				i--;
1837 			}
1838 			dsp->tx_delay[0] = CMX_BUFF_HALF; /* (infinite) delay */
1839 			dsp->rx_delay[0] = CMX_BUFF_HALF; /* (infinite) delay */
1840 		}
1841 	}
1842 
1843 	/* if next event would be in the past ... */
1844 	if ((s32)(dsp_spl_jiffies + dsp_tics-jiffies) <= 0)
1845 		dsp_spl_jiffies = jiffies + 1;
1846 	else
1847 		dsp_spl_jiffies += dsp_tics;
1848 
1849 	dsp_spl_tl.expires = dsp_spl_jiffies;
1850 	add_timer(&dsp_spl_tl);
1851 
1852 	/* unlock */
1853 	spin_unlock_irqrestore(&dsp_lock, flags);
1854 }
1855 
1856 /*
1857  * audio data is transmitted from upper layer to the dsp
1858  */
1859 void
1860 dsp_cmx_transmit(struct dsp *dsp, struct sk_buff *skb)
1861 {
1862 	u_int w, ww;
1863 	u8 *d, *p;
1864 	int space; /* todo: , l = skb->len; */
1865 #ifdef CMX_TX_DEBUG
1866 	char debugbuf[256] = "";
1867 #endif
1868 
1869 	/* check if there is enough space, and then copy */
1870 	w = dsp->tx_W;
1871 	ww = dsp->tx_R;
1872 	p = dsp->tx_buff;
1873 	d = skb->data;
1874 	space = (ww - w - 1) & CMX_BUFF_MASK;
1875 	/* write-pointer should not overrun nor reach read pointer */
1876 	if (space < skb->len) {
1877 		/* write to the space we have left */
1878 		ww = (ww - 1) & CMX_BUFF_MASK; /* end one byte prior tx_R */
1879 		if (dsp_debug & DEBUG_DSP_CLOCK)
1880 			printk(KERN_DEBUG "%s: TX overflow space=%d skb->len="
1881 			       "%d, w=0x%04x, ww=0x%04x\n", __func__, space,
1882 			       skb->len, w, ww);
1883 	} else
1884 		/* write until all byte are copied */
1885 		ww = (w + skb->len) & CMX_BUFF_MASK;
1886 	dsp->tx_W = ww;
1887 		/* show current buffer */
1888 #ifdef CMX_DEBUG
1889 	printk(KERN_DEBUG
1890 	       "cmx_transmit(dsp=%lx) %d bytes to 0x%x-0x%x. %s\n",
1891 	       (u_long)dsp, (ww - w) & CMX_BUFF_MASK, w, ww, dsp->name);
1892 #endif
1893 
1894 	/* copy transmit data to tx-buffer */
1895 #ifdef CMX_TX_DEBUG
1896 	sprintf(debugbuf, "TX getting (%04x-%04x)%p: ", w, ww, p);
1897 #endif
1898 	while (w != ww) {
1899 #ifdef CMX_TX_DEBUG
1900 		if (strlen(debugbuf) < 48)
1901 			sprintf(debugbuf + strlen(debugbuf), " %02x", *d);
1902 #endif
1903 		p[w] = *d++;
1904 		w = (w + 1) & CMX_BUFF_MASK;
1905 	}
1906 #ifdef CMX_TX_DEBUG
1907 	printk(KERN_DEBUG "%s\n", debugbuf);
1908 #endif
1909 
1910 }
1911 
1912 /*
1913  * hdlc data is received from card and sent to all members.
1914  */
1915 void
1916 dsp_cmx_hdlc(struct dsp *dsp, struct sk_buff *skb)
1917 {
1918 	struct sk_buff *nskb = NULL;
1919 	struct dsp_conf_member *member;
1920 	struct mISDNhead *hh;
1921 
1922 	/* not if not active */
1923 	if (!dsp->b_active)
1924 		return;
1925 
1926 	/* check if we have sompen */
1927 	if (skb->len < 1)
1928 		return;
1929 
1930 	/* no conf */
1931 	if (!dsp->conf) {
1932 		/* in case of software echo */
1933 		if (dsp->echo.software) {
1934 			nskb = skb_clone(skb, GFP_ATOMIC);
1935 			if (nskb) {
1936 				hh = mISDN_HEAD_P(nskb);
1937 				hh->prim = PH_DATA_REQ;
1938 				hh->id = 0;
1939 				skb_queue_tail(&dsp->sendq, nskb);
1940 				schedule_work(&dsp->workq);
1941 			}
1942 		}
1943 		return;
1944 	}
1945 	/* in case of hardware conference */
1946 	if (dsp->conf->hardware)
1947 		return;
1948 	list_for_each_entry(member, &dsp->conf->mlist, list) {
1949 		if (dsp->echo.software || member->dsp != dsp) {
1950 			nskb = skb_clone(skb, GFP_ATOMIC);
1951 			if (nskb) {
1952 				hh = mISDN_HEAD_P(nskb);
1953 				hh->prim = PH_DATA_REQ;
1954 				hh->id = 0;
1955 				skb_queue_tail(&member->dsp->sendq, nskb);
1956 				schedule_work(&member->dsp->workq);
1957 			}
1958 		}
1959 	}
1960 }
1961