1 /*
2 * Copyright (C) 2010 Bruno Randolf <br1@einfach.org>
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19 #include "ath5k.h"
20 #include "reg.h"
21 #include "debug.h"
22 #include "ani.h"
23
24 /**
25 * DOC: Basic ANI Operation
26 *
27 * Adaptive Noise Immunity (ANI) controls five noise immunity parameters
28 * depending on the amount of interference in the environment, increasing
29 * or reducing sensitivity as necessary.
30 *
31 * The parameters are:
32 *
33 * - "noise immunity"
34 *
35 * - "spur immunity"
36 *
37 * - "firstep level"
38 *
39 * - "OFDM weak signal detection"
40 *
41 * - "CCK weak signal detection"
42 *
43 * Basically we look at the amount of ODFM and CCK timing errors we get and then
44 * raise or lower immunity accordingly by setting one or more of these
45 * parameters.
46 *
47 * Newer chipsets have PHY error counters in hardware which will generate a MIB
48 * interrupt when they overflow. Older hardware has too enable PHY error frames
49 * by setting a RX flag and then count every single PHY error. When a specified
50 * threshold of errors has been reached we will raise immunity.
51 * Also we regularly check the amount of errors and lower or raise immunity as
52 * necessary.
53 */
54
55
56 /***********************\
57 * ANI parameter control *
58 \***********************/
59
60 /**
61 * ath5k_ani_set_noise_immunity_level() - Set noise immunity level
62 * @ah: The &struct ath5k_hw
63 * @level: level between 0 and @ATH5K_ANI_MAX_NOISE_IMM_LVL
64 */
65 void
ath5k_ani_set_noise_immunity_level(struct ath5k_hw * ah,int level)66 ath5k_ani_set_noise_immunity_level(struct ath5k_hw *ah, int level)
67 {
68 /* TODO:
69 * ANI documents suggest the following five levels to use, but the HAL
70 * and ath9k use only the last two levels, making this
71 * essentially an on/off option. There *may* be a reason for this (???),
72 * so i stick with the HAL version for now...
73 */
74 #if 0
75 static const s8 lo[] = { -52, -56, -60, -64, -70 };
76 static const s8 hi[] = { -18, -18, -16, -14, -12 };
77 static const s8 sz[] = { -34, -41, -48, -55, -62 };
78 static const s8 fr[] = { -70, -72, -75, -78, -80 };
79 #else
80 static const s8 lo[] = { -64, -70 };
81 static const s8 hi[] = { -14, -12 };
82 static const s8 sz[] = { -55, -62 };
83 static const s8 fr[] = { -78, -80 };
84 #endif
85 if (level < 0 || level >= ARRAY_SIZE(sz)) {
86 ATH5K_ERR(ah, "noise immunity level %d out of range",
87 level);
88 return;
89 }
90
91 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_DESIRED_SIZE,
92 AR5K_PHY_DESIRED_SIZE_TOT, sz[level]);
93 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_AGCCOARSE,
94 AR5K_PHY_AGCCOARSE_LO, lo[level]);
95 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_AGCCOARSE,
96 AR5K_PHY_AGCCOARSE_HI, hi[level]);
97 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SIG,
98 AR5K_PHY_SIG_FIRPWR, fr[level]);
99
100 ah->ani_state.noise_imm_level = level;
101 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "new level %d", level);
102 }
103
104 /**
105 * ath5k_ani_set_spur_immunity_level() - Set spur immunity level
106 * @ah: The &struct ath5k_hw
107 * @level: level between 0 and @max_spur_level (the maximum level is dependent
108 * on the chip revision).
109 */
110 void
ath5k_ani_set_spur_immunity_level(struct ath5k_hw * ah,int level)111 ath5k_ani_set_spur_immunity_level(struct ath5k_hw *ah, int level)
112 {
113 static const int val[] = { 2, 4, 6, 8, 10, 12, 14, 16 };
114
115 if (level < 0 || level >= ARRAY_SIZE(val) ||
116 level > ah->ani_state.max_spur_level) {
117 ATH5K_ERR(ah, "spur immunity level %d out of range",
118 level);
119 return;
120 }
121
122 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_OFDM_SELFCORR,
123 AR5K_PHY_OFDM_SELFCORR_CYPWR_THR1, val[level]);
124
125 ah->ani_state.spur_level = level;
126 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "new level %d", level);
127 }
128
129 /**
130 * ath5k_ani_set_firstep_level() - Set "firstep" level
131 * @ah: The &struct ath5k_hw
132 * @level: level between 0 and @ATH5K_ANI_MAX_FIRSTEP_LVL
133 */
134 void
ath5k_ani_set_firstep_level(struct ath5k_hw * ah,int level)135 ath5k_ani_set_firstep_level(struct ath5k_hw *ah, int level)
136 {
137 static const int val[] = { 0, 4, 8 };
138
139 if (level < 0 || level >= ARRAY_SIZE(val)) {
140 ATH5K_ERR(ah, "firstep level %d out of range", level);
141 return;
142 }
143
144 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SIG,
145 AR5K_PHY_SIG_FIRSTEP, val[level]);
146
147 ah->ani_state.firstep_level = level;
148 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "new level %d", level);
149 }
150
151 /**
152 * ath5k_ani_set_ofdm_weak_signal_detection() - Set OFDM weak signal detection
153 * @ah: The &struct ath5k_hw
154 * @on: turn on or off
155 */
156 void
ath5k_ani_set_ofdm_weak_signal_detection(struct ath5k_hw * ah,bool on)157 ath5k_ani_set_ofdm_weak_signal_detection(struct ath5k_hw *ah, bool on)
158 {
159 static const int m1l[] = { 127, 50 };
160 static const int m2l[] = { 127, 40 };
161 static const int m1[] = { 127, 0x4d };
162 static const int m2[] = { 127, 0x40 };
163 static const int m2cnt[] = { 31, 16 };
164 static const int m2lcnt[] = { 63, 48 };
165
166 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
167 AR5K_PHY_WEAK_OFDM_LOW_THR_M1, m1l[on]);
168 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
169 AR5K_PHY_WEAK_OFDM_LOW_THR_M2, m2l[on]);
170 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_HIGH_THR,
171 AR5K_PHY_WEAK_OFDM_HIGH_THR_M1, m1[on]);
172 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_HIGH_THR,
173 AR5K_PHY_WEAK_OFDM_HIGH_THR_M2, m2[on]);
174 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_HIGH_THR,
175 AR5K_PHY_WEAK_OFDM_HIGH_THR_M2_COUNT, m2cnt[on]);
176 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
177 AR5K_PHY_WEAK_OFDM_LOW_THR_M2_COUNT, m2lcnt[on]);
178
179 if (on)
180 AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
181 AR5K_PHY_WEAK_OFDM_LOW_THR_SELFCOR_EN);
182 else
183 AR5K_REG_DISABLE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
184 AR5K_PHY_WEAK_OFDM_LOW_THR_SELFCOR_EN);
185
186 ah->ani_state.ofdm_weak_sig = on;
187 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "turned %s",
188 on ? "on" : "off");
189 }
190
191 /**
192 * ath5k_ani_set_cck_weak_signal_detection() - Set CCK weak signal detection
193 * @ah: The &struct ath5k_hw
194 * @on: turn on or off
195 */
196 void
ath5k_ani_set_cck_weak_signal_detection(struct ath5k_hw * ah,bool on)197 ath5k_ani_set_cck_weak_signal_detection(struct ath5k_hw *ah, bool on)
198 {
199 static const int val[] = { 8, 6 };
200 AR5K_REG_WRITE_BITS(ah, AR5K_PHY_CCK_CROSSCORR,
201 AR5K_PHY_CCK_CROSSCORR_WEAK_SIG_THR, val[on]);
202 ah->ani_state.cck_weak_sig = on;
203 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "turned %s",
204 on ? "on" : "off");
205 }
206
207
208 /***************\
209 * ANI algorithm *
210 \***************/
211
212 /**
213 * ath5k_ani_raise_immunity() - Increase noise immunity
214 * @ah: The &struct ath5k_hw
215 * @as: The &struct ath5k_ani_state
216 * @ofdm_trigger: If this is true we are called because of too many OFDM errors,
217 * the algorithm will tune more parameters then.
218 *
219 * Try to raise noise immunity (=decrease sensitivity) in several steps
220 * depending on the average RSSI of the beacons we received.
221 */
222 static void
ath5k_ani_raise_immunity(struct ath5k_hw * ah,struct ath5k_ani_state * as,bool ofdm_trigger)223 ath5k_ani_raise_immunity(struct ath5k_hw *ah, struct ath5k_ani_state *as,
224 bool ofdm_trigger)
225 {
226 int rssi = ewma_beacon_rssi_read(&ah->ah_beacon_rssi_avg);
227
228 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "raise immunity (%s)",
229 ofdm_trigger ? "ODFM" : "CCK");
230
231 /* first: raise noise immunity */
232 if (as->noise_imm_level < ATH5K_ANI_MAX_NOISE_IMM_LVL) {
233 ath5k_ani_set_noise_immunity_level(ah, as->noise_imm_level + 1);
234 return;
235 }
236
237 /* only OFDM: raise spur immunity level */
238 if (ofdm_trigger &&
239 as->spur_level < ah->ani_state.max_spur_level) {
240 ath5k_ani_set_spur_immunity_level(ah, as->spur_level + 1);
241 return;
242 }
243
244 /* AP mode */
245 if (ah->opmode == NL80211_IFTYPE_AP) {
246 if (as->firstep_level < ATH5K_ANI_MAX_FIRSTEP_LVL)
247 ath5k_ani_set_firstep_level(ah, as->firstep_level + 1);
248 return;
249 }
250
251 /* STA and IBSS mode */
252
253 /* TODO: for IBSS mode it would be better to keep a beacon RSSI average
254 * per each neighbour node and use the minimum of these, to make sure we
255 * don't shut out a remote node by raising immunity too high. */
256
257 if (rssi > ATH5K_ANI_RSSI_THR_HIGH) {
258 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
259 "beacon RSSI high");
260 /* only OFDM: beacon RSSI is high, we can disable ODFM weak
261 * signal detection */
262 if (ofdm_trigger && as->ofdm_weak_sig) {
263 ath5k_ani_set_ofdm_weak_signal_detection(ah, false);
264 ath5k_ani_set_spur_immunity_level(ah, 0);
265 return;
266 }
267 /* as a last resort or CCK: raise firstep level */
268 if (as->firstep_level < ATH5K_ANI_MAX_FIRSTEP_LVL) {
269 ath5k_ani_set_firstep_level(ah, as->firstep_level + 1);
270 return;
271 }
272 } else if (rssi > ATH5K_ANI_RSSI_THR_LOW) {
273 /* beacon RSSI in mid range, we need OFDM weak signal detect,
274 * but can raise firstep level */
275 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
276 "beacon RSSI mid");
277 if (ofdm_trigger && !as->ofdm_weak_sig)
278 ath5k_ani_set_ofdm_weak_signal_detection(ah, true);
279 if (as->firstep_level < ATH5K_ANI_MAX_FIRSTEP_LVL)
280 ath5k_ani_set_firstep_level(ah, as->firstep_level + 1);
281 return;
282 } else if (ah->ah_current_channel->band == NL80211_BAND_2GHZ) {
283 /* beacon RSSI is low. in B/G mode turn of OFDM weak signal
284 * detect and zero firstep level to maximize CCK sensitivity */
285 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
286 "beacon RSSI low, 2GHz");
287 if (ofdm_trigger && as->ofdm_weak_sig)
288 ath5k_ani_set_ofdm_weak_signal_detection(ah, false);
289 if (as->firstep_level > 0)
290 ath5k_ani_set_firstep_level(ah, 0);
291 return;
292 }
293
294 /* TODO: why not?:
295 if (as->cck_weak_sig == true) {
296 ath5k_ani_set_cck_weak_signal_detection(ah, false);
297 }
298 */
299 }
300
301 /**
302 * ath5k_ani_lower_immunity() - Decrease noise immunity
303 * @ah: The &struct ath5k_hw
304 * @as: The &struct ath5k_ani_state
305 *
306 * Try to lower noise immunity (=increase sensitivity) in several steps
307 * depending on the average RSSI of the beacons we received.
308 */
309 static void
ath5k_ani_lower_immunity(struct ath5k_hw * ah,struct ath5k_ani_state * as)310 ath5k_ani_lower_immunity(struct ath5k_hw *ah, struct ath5k_ani_state *as)
311 {
312 int rssi = ewma_beacon_rssi_read(&ah->ah_beacon_rssi_avg);
313
314 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "lower immunity");
315
316 if (ah->opmode == NL80211_IFTYPE_AP) {
317 /* AP mode */
318 if (as->firstep_level > 0) {
319 ath5k_ani_set_firstep_level(ah, as->firstep_level - 1);
320 return;
321 }
322 } else {
323 /* STA and IBSS mode (see TODO above) */
324 if (rssi > ATH5K_ANI_RSSI_THR_HIGH) {
325 /* beacon signal is high, leave OFDM weak signal
326 * detection off or it may oscillate
327 * TODO: who said it's off??? */
328 } else if (rssi > ATH5K_ANI_RSSI_THR_LOW) {
329 /* beacon RSSI is mid-range: turn on ODFM weak signal
330 * detection and next, lower firstep level */
331 if (!as->ofdm_weak_sig) {
332 ath5k_ani_set_ofdm_weak_signal_detection(ah,
333 true);
334 return;
335 }
336 if (as->firstep_level > 0) {
337 ath5k_ani_set_firstep_level(ah,
338 as->firstep_level - 1);
339 return;
340 }
341 } else {
342 /* beacon signal is low: only reduce firstep level */
343 if (as->firstep_level > 0) {
344 ath5k_ani_set_firstep_level(ah,
345 as->firstep_level - 1);
346 return;
347 }
348 }
349 }
350
351 /* all modes */
352 if (as->spur_level > 0) {
353 ath5k_ani_set_spur_immunity_level(ah, as->spur_level - 1);
354 return;
355 }
356
357 /* finally, reduce noise immunity */
358 if (as->noise_imm_level > 0) {
359 ath5k_ani_set_noise_immunity_level(ah, as->noise_imm_level - 1);
360 return;
361 }
362 }
363
364 /**
365 * ath5k_hw_ani_get_listen_time() - Update counters and return listening time
366 * @ah: The &struct ath5k_hw
367 * @as: The &struct ath5k_ani_state
368 *
369 * Return an approximation of the time spent "listening" in milliseconds (ms)
370 * since the last call of this function.
371 * Save a snapshot of the counter values for debugging/statistics.
372 */
373 static int
ath5k_hw_ani_get_listen_time(struct ath5k_hw * ah,struct ath5k_ani_state * as)374 ath5k_hw_ani_get_listen_time(struct ath5k_hw *ah, struct ath5k_ani_state *as)
375 {
376 struct ath_common *common = ath5k_hw_common(ah);
377 int listen;
378
379 spin_lock_bh(&common->cc_lock);
380
381 ath_hw_cycle_counters_update(common);
382 memcpy(&as->last_cc, &common->cc_ani, sizeof(as->last_cc));
383
384 /* clears common->cc_ani */
385 listen = ath_hw_get_listen_time(common);
386
387 spin_unlock_bh(&common->cc_lock);
388
389 return listen;
390 }
391
392 /**
393 * ath5k_ani_save_and_clear_phy_errors() - Clear and save PHY error counters
394 * @ah: The &struct ath5k_hw
395 * @as: The &struct ath5k_ani_state
396 *
397 * Clear the PHY error counters as soon as possible, since this might be called
398 * from a MIB interrupt and we want to make sure we don't get interrupted again.
399 * Add the count of CCK and OFDM errors to our internal state, so it can be used
400 * by the algorithm later.
401 *
402 * Will be called from interrupt and tasklet context.
403 * Returns 0 if both counters are zero.
404 */
405 static int
ath5k_ani_save_and_clear_phy_errors(struct ath5k_hw * ah,struct ath5k_ani_state * as)406 ath5k_ani_save_and_clear_phy_errors(struct ath5k_hw *ah,
407 struct ath5k_ani_state *as)
408 {
409 unsigned int ofdm_err, cck_err;
410
411 if (!ah->ah_capabilities.cap_has_phyerr_counters)
412 return 0;
413
414 ofdm_err = ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT1);
415 cck_err = ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT2);
416
417 /* reset counters first, we might be in a hurry (interrupt) */
418 ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_OFDM_TRIG_HIGH,
419 AR5K_PHYERR_CNT1);
420 ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_CCK_TRIG_HIGH,
421 AR5K_PHYERR_CNT2);
422
423 ofdm_err = ATH5K_ANI_OFDM_TRIG_HIGH - (ATH5K_PHYERR_CNT_MAX - ofdm_err);
424 cck_err = ATH5K_ANI_CCK_TRIG_HIGH - (ATH5K_PHYERR_CNT_MAX - cck_err);
425
426 /* sometimes both can be zero, especially when there is a superfluous
427 * second interrupt. detect that here and return an error. */
428 if (ofdm_err <= 0 && cck_err <= 0)
429 return 0;
430
431 /* avoid negative values should one of the registers overflow */
432 if (ofdm_err > 0) {
433 as->ofdm_errors += ofdm_err;
434 as->sum_ofdm_errors += ofdm_err;
435 }
436 if (cck_err > 0) {
437 as->cck_errors += cck_err;
438 as->sum_cck_errors += cck_err;
439 }
440 return 1;
441 }
442
443 /**
444 * ath5k_ani_period_restart() - Restart ANI period
445 * @as: The &struct ath5k_ani_state
446 *
447 * Just reset counters, so they are clear for the next "ani period".
448 */
449 static void
ath5k_ani_period_restart(struct ath5k_ani_state * as)450 ath5k_ani_period_restart(struct ath5k_ani_state *as)
451 {
452 /* keep last values for debugging */
453 as->last_ofdm_errors = as->ofdm_errors;
454 as->last_cck_errors = as->cck_errors;
455 as->last_listen = as->listen_time;
456
457 as->ofdm_errors = 0;
458 as->cck_errors = 0;
459 as->listen_time = 0;
460 }
461
462 /**
463 * ath5k_ani_calibration() - The main ANI calibration function
464 * @ah: The &struct ath5k_hw
465 *
466 * We count OFDM and CCK errors relative to the time where we did not send or
467 * receive ("listen" time) and raise or lower immunity accordingly.
468 * This is called regularly (every second) from the calibration timer, but also
469 * when an error threshold has been reached.
470 *
471 * In order to synchronize access from different contexts, this should be
472 * called only indirectly by scheduling the ANI tasklet!
473 */
474 void
ath5k_ani_calibration(struct ath5k_hw * ah)475 ath5k_ani_calibration(struct ath5k_hw *ah)
476 {
477 struct ath5k_ani_state *as = &ah->ani_state;
478 int listen, ofdm_high, ofdm_low, cck_high, cck_low;
479
480 /* get listen time since last call and add it to the counter because we
481 * might not have restarted the "ani period" last time.
482 * always do this to calculate the busy time also in manual mode */
483 listen = ath5k_hw_ani_get_listen_time(ah, as);
484 as->listen_time += listen;
485
486 if (as->ani_mode != ATH5K_ANI_MODE_AUTO)
487 return;
488
489 ath5k_ani_save_and_clear_phy_errors(ah, as);
490
491 ofdm_high = as->listen_time * ATH5K_ANI_OFDM_TRIG_HIGH / 1000;
492 cck_high = as->listen_time * ATH5K_ANI_CCK_TRIG_HIGH / 1000;
493 ofdm_low = as->listen_time * ATH5K_ANI_OFDM_TRIG_LOW / 1000;
494 cck_low = as->listen_time * ATH5K_ANI_CCK_TRIG_LOW / 1000;
495
496 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
497 "listen %d (now %d)", as->listen_time, listen);
498 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
499 "check high ofdm %d/%d cck %d/%d",
500 as->ofdm_errors, ofdm_high, as->cck_errors, cck_high);
501
502 if (as->ofdm_errors > ofdm_high || as->cck_errors > cck_high) {
503 /* too many PHY errors - we have to raise immunity */
504 bool ofdm_flag = as->ofdm_errors > ofdm_high;
505 ath5k_ani_raise_immunity(ah, as, ofdm_flag);
506 ath5k_ani_period_restart(as);
507
508 } else if (as->listen_time > 5 * ATH5K_ANI_LISTEN_PERIOD) {
509 /* If more than 5 (TODO: why 5?) periods have passed and we got
510 * relatively little errors we can try to lower immunity */
511 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
512 "check low ofdm %d/%d cck %d/%d",
513 as->ofdm_errors, ofdm_low, as->cck_errors, cck_low);
514
515 if (as->ofdm_errors <= ofdm_low && as->cck_errors <= cck_low)
516 ath5k_ani_lower_immunity(ah, as);
517
518 ath5k_ani_period_restart(as);
519 }
520 }
521
522
523 /*******************\
524 * Interrupt handler *
525 \*******************/
526
527 /**
528 * ath5k_ani_mib_intr() - Interrupt handler for ANI MIB counters
529 * @ah: The &struct ath5k_hw
530 *
531 * Just read & reset the registers quickly, so they don't generate more
532 * interrupts, save the counters and schedule the tasklet to decide whether
533 * to raise immunity or not.
534 *
535 * We just need to handle PHY error counters, ath5k_hw_update_mib_counters()
536 * should take care of all "normal" MIB interrupts.
537 */
538 void
ath5k_ani_mib_intr(struct ath5k_hw * ah)539 ath5k_ani_mib_intr(struct ath5k_hw *ah)
540 {
541 struct ath5k_ani_state *as = &ah->ani_state;
542
543 /* nothing to do here if HW does not have PHY error counters - they
544 * can't be the reason for the MIB interrupt then */
545 if (!ah->ah_capabilities.cap_has_phyerr_counters)
546 return;
547
548 /* not in use but clear anyways */
549 ath5k_hw_reg_write(ah, 0, AR5K_OFDM_FIL_CNT);
550 ath5k_hw_reg_write(ah, 0, AR5K_CCK_FIL_CNT);
551
552 if (ah->ani_state.ani_mode != ATH5K_ANI_MODE_AUTO)
553 return;
554
555 /* If one of the errors triggered, we can get a superfluous second
556 * interrupt, even though we have already reset the register. The
557 * function detects that so we can return early. */
558 if (ath5k_ani_save_and_clear_phy_errors(ah, as) == 0)
559 return;
560
561 if (as->ofdm_errors > ATH5K_ANI_OFDM_TRIG_HIGH ||
562 as->cck_errors > ATH5K_ANI_CCK_TRIG_HIGH)
563 tasklet_schedule(&ah->ani_tasklet);
564 }
565
566 /**
567 * ath5k_ani_phy_error_report - Used by older HW to report PHY errors
568 *
569 * @ah: The &struct ath5k_hw
570 * @phyerr: One of enum ath5k_phy_error_code
571 *
572 * This is used by hardware without PHY error counters to report PHY errors
573 * on a frame-by-frame basis, instead of the interrupt.
574 */
575 void
ath5k_ani_phy_error_report(struct ath5k_hw * ah,enum ath5k_phy_error_code phyerr)576 ath5k_ani_phy_error_report(struct ath5k_hw *ah,
577 enum ath5k_phy_error_code phyerr)
578 {
579 struct ath5k_ani_state *as = &ah->ani_state;
580
581 if (phyerr == AR5K_RX_PHY_ERROR_OFDM_TIMING) {
582 as->ofdm_errors++;
583 if (as->ofdm_errors > ATH5K_ANI_OFDM_TRIG_HIGH)
584 tasklet_schedule(&ah->ani_tasklet);
585 } else if (phyerr == AR5K_RX_PHY_ERROR_CCK_TIMING) {
586 as->cck_errors++;
587 if (as->cck_errors > ATH5K_ANI_CCK_TRIG_HIGH)
588 tasklet_schedule(&ah->ani_tasklet);
589 }
590 }
591
592
593 /****************\
594 * Initialization *
595 \****************/
596
597 /**
598 * ath5k_enable_phy_err_counters() - Enable PHY error counters
599 * @ah: The &struct ath5k_hw
600 *
601 * Enable PHY error counters for OFDM and CCK timing errors.
602 */
603 static void
ath5k_enable_phy_err_counters(struct ath5k_hw * ah)604 ath5k_enable_phy_err_counters(struct ath5k_hw *ah)
605 {
606 ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_OFDM_TRIG_HIGH,
607 AR5K_PHYERR_CNT1);
608 ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_CCK_TRIG_HIGH,
609 AR5K_PHYERR_CNT2);
610 ath5k_hw_reg_write(ah, AR5K_PHY_ERR_FIL_OFDM, AR5K_PHYERR_CNT1_MASK);
611 ath5k_hw_reg_write(ah, AR5K_PHY_ERR_FIL_CCK, AR5K_PHYERR_CNT2_MASK);
612
613 /* not in use */
614 ath5k_hw_reg_write(ah, 0, AR5K_OFDM_FIL_CNT);
615 ath5k_hw_reg_write(ah, 0, AR5K_CCK_FIL_CNT);
616 }
617
618 /**
619 * ath5k_disable_phy_err_counters() - Disable PHY error counters
620 * @ah: The &struct ath5k_hw
621 *
622 * Disable PHY error counters for OFDM and CCK timing errors.
623 */
624 static void
ath5k_disable_phy_err_counters(struct ath5k_hw * ah)625 ath5k_disable_phy_err_counters(struct ath5k_hw *ah)
626 {
627 ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT1);
628 ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT2);
629 ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT1_MASK);
630 ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT2_MASK);
631
632 /* not in use */
633 ath5k_hw_reg_write(ah, 0, AR5K_OFDM_FIL_CNT);
634 ath5k_hw_reg_write(ah, 0, AR5K_CCK_FIL_CNT);
635 }
636
637 /**
638 * ath5k_ani_init() - Initialize ANI
639 * @ah: The &struct ath5k_hw
640 * @mode: One of enum ath5k_ani_mode
641 *
642 * Initialize ANI according to mode.
643 */
644 void
ath5k_ani_init(struct ath5k_hw * ah,enum ath5k_ani_mode mode)645 ath5k_ani_init(struct ath5k_hw *ah, enum ath5k_ani_mode mode)
646 {
647 /* ANI is only possible on 5212 and newer */
648 if (ah->ah_version < AR5K_AR5212)
649 return;
650
651 if (mode < ATH5K_ANI_MODE_OFF || mode > ATH5K_ANI_MODE_AUTO) {
652 ATH5K_ERR(ah, "ANI mode %d out of range", mode);
653 return;
654 }
655
656 /* clear old state information */
657 memset(&ah->ani_state, 0, sizeof(ah->ani_state));
658
659 /* older hardware has more spur levels than newer */
660 if (ah->ah_mac_srev < AR5K_SREV_AR2414)
661 ah->ani_state.max_spur_level = 7;
662 else
663 ah->ani_state.max_spur_level = 2;
664
665 /* initial values for our ani parameters */
666 if (mode == ATH5K_ANI_MODE_OFF) {
667 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "ANI off\n");
668 } else if (mode == ATH5K_ANI_MODE_MANUAL_LOW) {
669 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
670 "ANI manual low -> high sensitivity\n");
671 ath5k_ani_set_noise_immunity_level(ah, 0);
672 ath5k_ani_set_spur_immunity_level(ah, 0);
673 ath5k_ani_set_firstep_level(ah, 0);
674 ath5k_ani_set_ofdm_weak_signal_detection(ah, true);
675 ath5k_ani_set_cck_weak_signal_detection(ah, true);
676 } else if (mode == ATH5K_ANI_MODE_MANUAL_HIGH) {
677 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI,
678 "ANI manual high -> low sensitivity\n");
679 ath5k_ani_set_noise_immunity_level(ah,
680 ATH5K_ANI_MAX_NOISE_IMM_LVL);
681 ath5k_ani_set_spur_immunity_level(ah,
682 ah->ani_state.max_spur_level);
683 ath5k_ani_set_firstep_level(ah, ATH5K_ANI_MAX_FIRSTEP_LVL);
684 ath5k_ani_set_ofdm_weak_signal_detection(ah, false);
685 ath5k_ani_set_cck_weak_signal_detection(ah, false);
686 } else if (mode == ATH5K_ANI_MODE_AUTO) {
687 ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "ANI auto\n");
688 ath5k_ani_set_noise_immunity_level(ah, 0);
689 ath5k_ani_set_spur_immunity_level(ah, 0);
690 ath5k_ani_set_firstep_level(ah, 0);
691 ath5k_ani_set_ofdm_weak_signal_detection(ah, true);
692 ath5k_ani_set_cck_weak_signal_detection(ah, false);
693 }
694
695 /* newer hardware has PHY error counter registers which we can use to
696 * get OFDM and CCK error counts. older hardware has to set rxfilter and
697 * report every single PHY error by calling ath5k_ani_phy_error_report()
698 */
699 if (mode == ATH5K_ANI_MODE_AUTO) {
700 if (ah->ah_capabilities.cap_has_phyerr_counters)
701 ath5k_enable_phy_err_counters(ah);
702 else
703 ath5k_hw_set_rx_filter(ah, ath5k_hw_get_rx_filter(ah) |
704 AR5K_RX_FILTER_PHYERR);
705 } else {
706 if (ah->ah_capabilities.cap_has_phyerr_counters)
707 ath5k_disable_phy_err_counters(ah);
708 else
709 ath5k_hw_set_rx_filter(ah, ath5k_hw_get_rx_filter(ah) &
710 ~AR5K_RX_FILTER_PHYERR);
711 }
712
713 ah->ani_state.ani_mode = mode;
714 }
715
716
717 /**************\
718 * Debug output *
719 \**************/
720
721 #ifdef CONFIG_ATH5K_DEBUG
722
723 /**
724 * ath5k_ani_print_counters() - Print ANI counters
725 * @ah: The &struct ath5k_hw
726 *
727 * Used for debugging ANI
728 */
729 void
ath5k_ani_print_counters(struct ath5k_hw * ah)730 ath5k_ani_print_counters(struct ath5k_hw *ah)
731 {
732 /* clears too */
733 pr_notice("ACK fail\t%d\n", ath5k_hw_reg_read(ah, AR5K_ACK_FAIL));
734 pr_notice("RTS fail\t%d\n", ath5k_hw_reg_read(ah, AR5K_RTS_FAIL));
735 pr_notice("RTS success\t%d\n", ath5k_hw_reg_read(ah, AR5K_RTS_OK));
736 pr_notice("FCS error\t%d\n", ath5k_hw_reg_read(ah, AR5K_FCS_FAIL));
737
738 /* no clear */
739 pr_notice("tx\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_TX));
740 pr_notice("rx\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_RX));
741 pr_notice("busy\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_RXCLR));
742 pr_notice("cycles\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_CYCLE));
743
744 pr_notice("AR5K_PHYERR_CNT1\t%d\n",
745 ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT1));
746 pr_notice("AR5K_PHYERR_CNT2\t%d\n",
747 ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT2));
748 pr_notice("AR5K_OFDM_FIL_CNT\t%d\n",
749 ath5k_hw_reg_read(ah, AR5K_OFDM_FIL_CNT));
750 pr_notice("AR5K_CCK_FIL_CNT\t%d\n",
751 ath5k_hw_reg_read(ah, AR5K_CCK_FIL_CNT));
752 }
753
754 #endif
755