xref: /openbmc/linux/sound/usb/format.c (revision dc6a81c3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4 
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/usb.h>
8 #include <linux/usb/audio.h>
9 #include <linux/usb/audio-v2.h>
10 #include <linux/usb/audio-v3.h>
11 
12 #include <sound/core.h>
13 #include <sound/pcm.h>
14 
15 #include "usbaudio.h"
16 #include "card.h"
17 #include "quirks.h"
18 #include "helper.h"
19 #include "debug.h"
20 #include "clock.h"
21 #include "format.h"
22 
23 /*
24  * parse the audio format type I descriptor
25  * and returns the corresponding pcm format
26  *
27  * @dev: usb device
28  * @fp: audioformat record
29  * @format: the format tag (wFormatTag)
30  * @fmt: the format type descriptor (v1/v2) or AudioStreaming descriptor (v3)
31  */
32 static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
33 				     struct audioformat *fp,
34 				     u64 format, void *_fmt)
35 {
36 	int sample_width, sample_bytes;
37 	u64 pcm_formats = 0;
38 
39 	switch (fp->protocol) {
40 	case UAC_VERSION_1:
41 	default: {
42 		struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
43 		sample_width = fmt->bBitResolution;
44 		sample_bytes = fmt->bSubframeSize;
45 		format = 1ULL << format;
46 		break;
47 	}
48 
49 	case UAC_VERSION_2: {
50 		struct uac_format_type_i_ext_descriptor *fmt = _fmt;
51 		sample_width = fmt->bBitResolution;
52 		sample_bytes = fmt->bSubslotSize;
53 
54 		if (format & UAC2_FORMAT_TYPE_I_RAW_DATA) {
55 			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
56 			/* flag potentially raw DSD capable altsettings */
57 			fp->dsd_raw = true;
58 		}
59 
60 		format <<= 1;
61 		break;
62 	}
63 	case UAC_VERSION_3: {
64 		struct uac3_as_header_descriptor *as = _fmt;
65 
66 		sample_width = as->bBitResolution;
67 		sample_bytes = as->bSubslotSize;
68 
69 		if (format & UAC3_FORMAT_TYPE_I_RAW_DATA)
70 			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
71 
72 		format <<= 1;
73 		break;
74 	}
75 	}
76 
77 	fp->fmt_bits = sample_width;
78 
79 	if ((pcm_formats == 0) &&
80 	    (format == 0 || format == (1 << UAC_FORMAT_TYPE_I_UNDEFINED))) {
81 		/* some devices don't define this correctly... */
82 		usb_audio_info(chip, "%u:%d : format type 0 is detected, processed as PCM\n",
83 			fp->iface, fp->altsetting);
84 		format = 1 << UAC_FORMAT_TYPE_I_PCM;
85 	}
86 	if (format & (1 << UAC_FORMAT_TYPE_I_PCM)) {
87 		if (((chip->usb_id == USB_ID(0x0582, 0x0016)) ||
88 		     /* Edirol SD-90 */
89 		     (chip->usb_id == USB_ID(0x0582, 0x000c))) &&
90 		     /* Roland SC-D70 */
91 		    sample_width == 24 && sample_bytes == 2)
92 			sample_bytes = 3;
93 		else if (sample_width > sample_bytes * 8) {
94 			usb_audio_info(chip, "%u:%d : sample bitwidth %d in over sample bytes %d\n",
95 				 fp->iface, fp->altsetting,
96 				 sample_width, sample_bytes);
97 		}
98 		/* check the format byte size */
99 		switch (sample_bytes) {
100 		case 1:
101 			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
102 			break;
103 		case 2:
104 			if (snd_usb_is_big_endian_format(chip, fp))
105 				pcm_formats |= SNDRV_PCM_FMTBIT_S16_BE; /* grrr, big endian!! */
106 			else
107 				pcm_formats |= SNDRV_PCM_FMTBIT_S16_LE;
108 			break;
109 		case 3:
110 			if (snd_usb_is_big_endian_format(chip, fp))
111 				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3BE; /* grrr, big endian!! */
112 			else
113 				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3LE;
114 			break;
115 		case 4:
116 			pcm_formats |= SNDRV_PCM_FMTBIT_S32_LE;
117 			break;
118 		default:
119 			usb_audio_info(chip,
120 				 "%u:%d : unsupported sample bitwidth %d in %d bytes\n",
121 				 fp->iface, fp->altsetting,
122 				 sample_width, sample_bytes);
123 			break;
124 		}
125 	}
126 	if (format & (1 << UAC_FORMAT_TYPE_I_PCM8)) {
127 		/* Dallas DS4201 workaround: it advertises U8 format, but really
128 		   supports S8. */
129 		if (chip->usb_id == USB_ID(0x04fa, 0x4201))
130 			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
131 		else
132 			pcm_formats |= SNDRV_PCM_FMTBIT_U8;
133 	}
134 	if (format & (1 << UAC_FORMAT_TYPE_I_IEEE_FLOAT)) {
135 		pcm_formats |= SNDRV_PCM_FMTBIT_FLOAT_LE;
136 	}
137 	if (format & (1 << UAC_FORMAT_TYPE_I_ALAW)) {
138 		pcm_formats |= SNDRV_PCM_FMTBIT_A_LAW;
139 	}
140 	if (format & (1 << UAC_FORMAT_TYPE_I_MULAW)) {
141 		pcm_formats |= SNDRV_PCM_FMTBIT_MU_LAW;
142 	}
143 	if (format & ~0x3f) {
144 		usb_audio_info(chip,
145 			 "%u:%d : unsupported format bits %#llx\n",
146 			 fp->iface, fp->altsetting, format);
147 	}
148 
149 	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
150 
151 	return pcm_formats;
152 }
153 
154 
155 /*
156  * parse the format descriptor and stores the possible sample rates
157  * on the audioformat table (audio class v1).
158  *
159  * @dev: usb device
160  * @fp: audioformat record
161  * @fmt: the format descriptor
162  * @offset: the start offset of descriptor pointing the rate type
163  *          (7 for type I and II, 8 for type II)
164  */
165 static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audioformat *fp,
166 				       unsigned char *fmt, int offset)
167 {
168 	int nr_rates = fmt[offset];
169 
170 	if (fmt[0] < offset + 1 + 3 * (nr_rates ? nr_rates : 2)) {
171 		usb_audio_err(chip,
172 			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
173 			fp->iface, fp->altsetting);
174 		return -EINVAL;
175 	}
176 
177 	if (nr_rates) {
178 		/*
179 		 * build the rate table and bitmap flags
180 		 */
181 		int r, idx;
182 
183 		fp->rate_table = kmalloc_array(nr_rates, sizeof(int),
184 					       GFP_KERNEL);
185 		if (fp->rate_table == NULL)
186 			return -ENOMEM;
187 
188 		fp->nr_rates = 0;
189 		fp->rate_min = fp->rate_max = 0;
190 		for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
191 			unsigned int rate = combine_triple(&fmt[idx]);
192 			if (!rate)
193 				continue;
194 			/* C-Media CM6501 mislabels its 96 kHz altsetting */
195 			/* Terratec Aureon 7.1 USB C-Media 6206, too */
196 			if (rate == 48000 && nr_rates == 1 &&
197 			    (chip->usb_id == USB_ID(0x0d8c, 0x0201) ||
198 			     chip->usb_id == USB_ID(0x0d8c, 0x0102) ||
199 			     chip->usb_id == USB_ID(0x0ccd, 0x00b1)) &&
200 			    fp->altsetting == 5 && fp->maxpacksize == 392)
201 				rate = 96000;
202 			/* Creative VF0420/VF0470 Live Cams report 16 kHz instead of 8kHz */
203 			if (rate == 16000 &&
204 			    (chip->usb_id == USB_ID(0x041e, 0x4064) ||
205 			     chip->usb_id == USB_ID(0x041e, 0x4068)))
206 				rate = 8000;
207 
208 			fp->rate_table[fp->nr_rates] = rate;
209 			if (!fp->rate_min || rate < fp->rate_min)
210 				fp->rate_min = rate;
211 			if (!fp->rate_max || rate > fp->rate_max)
212 				fp->rate_max = rate;
213 			fp->rates |= snd_pcm_rate_to_rate_bit(rate);
214 			fp->nr_rates++;
215 		}
216 		if (!fp->nr_rates) {
217 			hwc_debug("All rates were zero. Skipping format!\n");
218 			return -EINVAL;
219 		}
220 	} else {
221 		/* continuous rates */
222 		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
223 		fp->rate_min = combine_triple(&fmt[offset + 1]);
224 		fp->rate_max = combine_triple(&fmt[offset + 4]);
225 	}
226 	return 0;
227 }
228 
229 /*
230  * Helper function to walk the array of sample rate triplets reported by
231  * the device. The problem is that we need to parse whole array first to
232  * get to know how many sample rates we have to expect.
233  * Then fp->rate_table can be allocated and filled.
234  */
235 static int parse_uac2_sample_rate_range(struct snd_usb_audio *chip,
236 					struct audioformat *fp, int nr_triplets,
237 					const unsigned char *data)
238 {
239 	int i, nr_rates = 0;
240 
241 	fp->rates = fp->rate_min = fp->rate_max = 0;
242 
243 	for (i = 0; i < nr_triplets; i++) {
244 		int min = combine_quad(&data[2 + 12 * i]);
245 		int max = combine_quad(&data[6 + 12 * i]);
246 		int res = combine_quad(&data[10 + 12 * i]);
247 		unsigned int rate;
248 
249 		if ((max < 0) || (min < 0) || (res < 0) || (max < min))
250 			continue;
251 
252 		/*
253 		 * for ranges with res == 1, we announce a continuous sample
254 		 * rate range, and this function should return 0 for no further
255 		 * parsing.
256 		 */
257 		if (res == 1) {
258 			fp->rate_min = min;
259 			fp->rate_max = max;
260 			fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
261 			return 0;
262 		}
263 
264 		for (rate = min; rate <= max; rate += res) {
265 			if (fp->rate_table)
266 				fp->rate_table[nr_rates] = rate;
267 			if (!fp->rate_min || rate < fp->rate_min)
268 				fp->rate_min = rate;
269 			if (!fp->rate_max || rate > fp->rate_max)
270 				fp->rate_max = rate;
271 			fp->rates |= snd_pcm_rate_to_rate_bit(rate);
272 
273 			nr_rates++;
274 			if (nr_rates >= MAX_NR_RATES) {
275 				usb_audio_err(chip, "invalid uac2 rates\n");
276 				break;
277 			}
278 
279 			/* avoid endless loop */
280 			if (res == 0)
281 				break;
282 		}
283 	}
284 
285 	return nr_rates;
286 }
287 
288 /* Line6 Helix series don't support the UAC2_CS_RANGE usb function
289  * call. Return a static table of known clock rates.
290  */
291 static int line6_parse_audio_format_rates_quirk(struct snd_usb_audio *chip,
292 						struct audioformat *fp)
293 {
294 	switch (chip->usb_id) {
295 	case USB_ID(0x0e41, 0x4241): /* Line6 Helix */
296 	case USB_ID(0x0e41, 0x4242): /* Line6 Helix Rack */
297 	case USB_ID(0x0e41, 0x4244): /* Line6 Helix LT */
298 	case USB_ID(0x0e41, 0x4246): /* Line6 HX-Stomp */
299 	case USB_ID(0x0e41, 0x4248): /* Line6 Helix >= fw 2.82 */
300 	case USB_ID(0x0e41, 0x4249): /* Line6 Helix Rack >= fw 2.82 */
301 	case USB_ID(0x0e41, 0x424a): /* Line6 Helix LT >= fw 2.82 */
302 		/* supported rates: 48Khz */
303 		kfree(fp->rate_table);
304 		fp->rate_table = kmalloc(sizeof(int), GFP_KERNEL);
305 		if (!fp->rate_table)
306 			return -ENOMEM;
307 		fp->nr_rates = 1;
308 		fp->rate_min = 48000;
309 		fp->rate_max = 48000;
310 		fp->rates = SNDRV_PCM_RATE_48000;
311 		fp->rate_table[0] = 48000;
312 		return 0;
313 	}
314 
315 	return -ENODEV;
316 }
317 
318 /*
319  * parse the format descriptor and stores the possible sample rates
320  * on the audioformat table (audio class v2 and v3).
321  */
322 static int parse_audio_format_rates_v2v3(struct snd_usb_audio *chip,
323 				       struct audioformat *fp)
324 {
325 	struct usb_device *dev = chip->dev;
326 	unsigned char tmp[2], *data;
327 	int nr_triplets, data_size, ret = 0, ret_l6;
328 	int clock = snd_usb_clock_find_source(chip, fp->protocol,
329 					      fp->clock, false);
330 
331 	if (clock < 0) {
332 		dev_err(&dev->dev,
333 			"%s(): unable to find clock source (clock %d)\n",
334 				__func__, clock);
335 		goto err;
336 	}
337 
338 	/* get the number of sample rates first by only fetching 2 bytes */
339 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
340 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
341 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
342 			      snd_usb_ctrl_intf(chip) | (clock << 8),
343 			      tmp, sizeof(tmp));
344 
345 	if (ret < 0) {
346 		/* line6 helix devices don't support UAC2_CS_CONTROL_SAM_FREQ call */
347 		ret_l6 = line6_parse_audio_format_rates_quirk(chip, fp);
348 		if (ret_l6 == -ENODEV) {
349 			/* no line6 device found continue showing the error */
350 			dev_err(&dev->dev,
351 				"%s(): unable to retrieve number of sample rates (clock %d)\n",
352 				__func__, clock);
353 			goto err;
354 		}
355 		if (ret_l6 == 0) {
356 			dev_info(&dev->dev,
357 				"%s(): unable to retrieve number of sample rates: set it to a predefined value (clock %d).\n",
358 				__func__, clock);
359 			return 0;
360 		}
361 		ret = ret_l6;
362 		goto err;
363 	}
364 
365 	nr_triplets = (tmp[1] << 8) | tmp[0];
366 	data_size = 2 + 12 * nr_triplets;
367 	data = kzalloc(data_size, GFP_KERNEL);
368 	if (!data) {
369 		ret = -ENOMEM;
370 		goto err;
371 	}
372 
373 	/* now get the full information */
374 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
375 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
376 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
377 			      snd_usb_ctrl_intf(chip) | (clock << 8),
378 			      data, data_size);
379 
380 	if (ret < 0) {
381 		dev_err(&dev->dev,
382 			"%s(): unable to retrieve sample rate range (clock %d)\n",
383 				__func__, clock);
384 		ret = -EINVAL;
385 		goto err_free;
386 	}
387 
388 	/* Call the triplet parser, and make sure fp->rate_table is NULL.
389 	 * We just use the return value to know how many sample rates we
390 	 * will have to deal with. */
391 	kfree(fp->rate_table);
392 	fp->rate_table = NULL;
393 	fp->nr_rates = parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);
394 
395 	if (fp->nr_rates == 0) {
396 		/* SNDRV_PCM_RATE_CONTINUOUS */
397 		ret = 0;
398 		goto err_free;
399 	}
400 
401 	fp->rate_table = kmalloc_array(fp->nr_rates, sizeof(int), GFP_KERNEL);
402 	if (!fp->rate_table) {
403 		ret = -ENOMEM;
404 		goto err_free;
405 	}
406 
407 	/* Call the triplet parser again, but this time, fp->rate_table is
408 	 * allocated, so the rates will be stored */
409 	parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);
410 
411 err_free:
412 	kfree(data);
413 err:
414 	return ret;
415 }
416 
417 /*
418  * parse the format type I and III descriptors
419  */
420 static int parse_audio_format_i(struct snd_usb_audio *chip,
421 				struct audioformat *fp, u64 format,
422 				void *_fmt)
423 {
424 	snd_pcm_format_t pcm_format;
425 	unsigned int fmt_type;
426 	int ret;
427 
428 	switch (fp->protocol) {
429 	default:
430 	case UAC_VERSION_1:
431 	case UAC_VERSION_2: {
432 		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;
433 
434 		fmt_type = fmt->bFormatType;
435 		break;
436 	}
437 	case UAC_VERSION_3: {
438 		/* fp->fmt_type is already set in this case */
439 		fmt_type = fp->fmt_type;
440 		break;
441 	}
442 	}
443 
444 	if (fmt_type == UAC_FORMAT_TYPE_III) {
445 		/* FIXME: the format type is really IECxxx
446 		 *        but we give normal PCM format to get the existing
447 		 *        apps working...
448 		 */
449 		switch (chip->usb_id) {
450 
451 		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
452 			if (chip->setup == 0x00 &&
453 			    fp->altsetting == 6)
454 				pcm_format = SNDRV_PCM_FORMAT_S16_BE;
455 			else
456 				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
457 			break;
458 		default:
459 			pcm_format = SNDRV_PCM_FORMAT_S16_LE;
460 		}
461 		fp->formats = pcm_format_to_bits(pcm_format);
462 	} else {
463 		fp->formats = parse_audio_format_i_type(chip, fp, format, _fmt);
464 		if (!fp->formats)
465 			return -EINVAL;
466 	}
467 
468 	/* gather possible sample rates */
469 	/* audio class v1 reports possible sample rates as part of the
470 	 * proprietary class specific descriptor.
471 	 * audio class v2 uses class specific EP0 range requests for that.
472 	 */
473 	switch (fp->protocol) {
474 	default:
475 	case UAC_VERSION_1: {
476 		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;
477 
478 		fp->channels = fmt->bNrChannels;
479 		ret = parse_audio_format_rates_v1(chip, fp, (unsigned char *) fmt, 7);
480 		break;
481 	}
482 	case UAC_VERSION_2:
483 	case UAC_VERSION_3: {
484 		/* fp->channels is already set in this case */
485 		ret = parse_audio_format_rates_v2v3(chip, fp);
486 		break;
487 	}
488 	}
489 
490 	if (fp->channels < 1) {
491 		usb_audio_err(chip,
492 			"%u:%d : invalid channels %d\n",
493 			fp->iface, fp->altsetting, fp->channels);
494 		return -EINVAL;
495 	}
496 
497 	return ret;
498 }
499 
500 /*
501  * parse the format type II descriptor
502  */
503 static int parse_audio_format_ii(struct snd_usb_audio *chip,
504 				 struct audioformat *fp,
505 				 u64 format, void *_fmt)
506 {
507 	int brate, framesize, ret;
508 
509 	switch (format) {
510 	case UAC_FORMAT_TYPE_II_AC3:
511 		/* FIXME: there is no AC3 format defined yet */
512 		// fp->formats = SNDRV_PCM_FMTBIT_AC3;
513 		fp->formats = SNDRV_PCM_FMTBIT_U8; /* temporary hack to receive byte streams */
514 		break;
515 	case UAC_FORMAT_TYPE_II_MPEG:
516 		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
517 		break;
518 	default:
519 		usb_audio_info(chip,
520 			 "%u:%d : unknown format tag %#llx is detected.  processed as MPEG.\n",
521 			 fp->iface, fp->altsetting, format);
522 		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
523 		break;
524 	}
525 
526 	fp->channels = 1;
527 
528 	switch (fp->protocol) {
529 	default:
530 	case UAC_VERSION_1: {
531 		struct uac_format_type_ii_discrete_descriptor *fmt = _fmt;
532 		brate = le16_to_cpu(fmt->wMaxBitRate);
533 		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
534 		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
535 		fp->frame_size = framesize;
536 		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 8); /* fmt[8..] sample rates */
537 		break;
538 	}
539 	case UAC_VERSION_2: {
540 		struct uac_format_type_ii_ext_descriptor *fmt = _fmt;
541 		brate = le16_to_cpu(fmt->wMaxBitRate);
542 		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
543 		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
544 		fp->frame_size = framesize;
545 		ret = parse_audio_format_rates_v2v3(chip, fp);
546 		break;
547 	}
548 	}
549 
550 	return ret;
551 }
552 
553 int snd_usb_parse_audio_format(struct snd_usb_audio *chip,
554 			       struct audioformat *fp, u64 format,
555 			       struct uac_format_type_i_continuous_descriptor *fmt,
556 			       int stream)
557 {
558 	int err;
559 
560 	switch (fmt->bFormatType) {
561 	case UAC_FORMAT_TYPE_I:
562 	case UAC_FORMAT_TYPE_III:
563 		err = parse_audio_format_i(chip, fp, format, fmt);
564 		break;
565 	case UAC_FORMAT_TYPE_II:
566 		err = parse_audio_format_ii(chip, fp, format, fmt);
567 		break;
568 	default:
569 		usb_audio_info(chip,
570 			 "%u:%d : format type %d is not supported yet\n",
571 			 fp->iface, fp->altsetting,
572 			 fmt->bFormatType);
573 		return -ENOTSUPP;
574 	}
575 	fp->fmt_type = fmt->bFormatType;
576 	if (err < 0)
577 		return err;
578 #if 1
579 	/* FIXME: temporary hack for extigy/audigy 2 nx/zs */
580 	/* extigy apparently supports sample rates other than 48k
581 	 * but not in ordinary way.  so we enable only 48k atm.
582 	 */
583 	if (chip->usb_id == USB_ID(0x041e, 0x3000) ||
584 	    chip->usb_id == USB_ID(0x041e, 0x3020) ||
585 	    chip->usb_id == USB_ID(0x041e, 0x3061)) {
586 		if (fmt->bFormatType == UAC_FORMAT_TYPE_I &&
587 		    fp->rates != SNDRV_PCM_RATE_48000 &&
588 		    fp->rates != SNDRV_PCM_RATE_96000)
589 			return -ENOTSUPP;
590 	}
591 #endif
592 	return 0;
593 }
594 
595 int snd_usb_parse_audio_format_v3(struct snd_usb_audio *chip,
596 			       struct audioformat *fp,
597 			       struct uac3_as_header_descriptor *as,
598 			       int stream)
599 {
600 	u64 format = le64_to_cpu(as->bmFormats);
601 	int err;
602 
603 	/*
604 	 * Type I format bits are D0..D6
605 	 * This test works because type IV is not supported
606 	 */
607 	if (format & 0x7f)
608 		fp->fmt_type = UAC_FORMAT_TYPE_I;
609 	else
610 		fp->fmt_type = UAC_FORMAT_TYPE_III;
611 
612 	err = parse_audio_format_i(chip, fp, format, as);
613 	if (err < 0)
614 		return err;
615 
616 	return 0;
617 }
618