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ALSA: usb-audio: workaround for iface reset issue

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The recently introduced sample rate validation code seems causing a
problem on some devices; namely, after performing this, the bus gets
screwed and it influences even on other USB devices.
As a quick workaround, perform it only for the necessary devices;
currently MOTU devices are known to need the valid altset checks, so
filter out other devices.

Fixes: 93db51d06b32 ("ALSA: usb-audio: Check valid altsetting at parsing rates for UAC2/3")
Reported-by: Jamie Heilman <jamie@audible.transient.net>
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1178203
Link: https://lore.kernel.org/r/20210123155842.22652-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2021-01-23 16:58:42 +01:00
parent 23b53d4417
commit fe773b8711
1 changed files with 11 additions and 0 deletions
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11
sound/usb/format.c
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@ -466,6 +466,17 @@ static int validate_sample_rate_table_v2v3(struct snd_usb_audio *chip,
unsigned int nr_rates;
int i, err;
/* performing the rate verification may lead to unexpected USB bus
* behavior afterwards by some unknown reason. Do this only for the
* known devices.
*/
switch (USB_ID_VENDOR(chip->usb_id)) {
case 0x07fd: /* MOTU */
break;
default:
return 0; /* don't perform the validation as default */
}
table = kcalloc(fp->nr_rates, sizeof(*table), GFP_KERNEL);
if (!table)
return -ENOMEM;