Hi Hui and Takashi, > On Dec 19, 2019, at 3:06 AM, Takashi Iwai <tiwai@xxxxxxx> wrote: > > On Wed, 18 Dec 2019 14:26:50 +0100, > Hui Wang wrote: >> >> Recently we found the headset-mic on the Dell Dock WD19 doesn't work >> anymore after s3 (s2i or deep), this problem could be workarounded by >> closeing (pcm_close) the app and then reopening (pcm_open) the app, so >> this bug is not easy to be detected by users. >> >> When problem happens, retire_capture_urb() could still be called >> periodically, but the size of captured data is always 0, it could be >> a firmware bug on the dock. Anyway I found after resuming, the >> snd_usb_pcm_prepare() will be called, and if we forcibly run >> set_format() to set the interface and its endpoint, the capture >> size will be normal again. This problem and workaound also apply to >> playback. >> >> To fix it in the kernel, add a quirk to let set_format() run >> forcibly once after resume. >> >> Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx> > > Thanks, the workaround looks reasonable. > I applied it now with Cc to stable. I am not entirely sure it’s a kernel bug. [1] [2] can also fix the issue. Since USB audio doesn’t have SNDRV_PCM_INFO_RESUME capability, userspace shouldn’t try to use snd_pcm_resume(). Commit [1] uses snd_pcm_drop() to make the device leave suspended state and the device behaves correctly with the fix. [1] https://gitlab.freedesktop.org/pulseaudio/pulseaudio/commit/f7b3537bbf9a6916ee3fd72a82025519b4c346f5 [2] https://gitlab.freedesktop.org/pulseaudio/pulseaudio/commit/734a00c849815a45697970d593068c301a04ebbb Kai-Heng > > > Takashi > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > https://mailman.alsa-project.org/mailman/listinfo/alsa-devel _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
