ALSA: usb-audio: set the interface format after resume on Dell WD19

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
closing (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@canonical.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191218132650.6303-1-hui.wang@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 19 insertions, 2 deletions

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 9c8930bb00c8..96298c767c76 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -510,11 +510,11 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
 		return -EINVAL;
 
-	if (fmt == subs->cur_audiofmt)
+	if (fmt == subs->cur_audiofmt && !subs->need_setup_fmt)
 		return 0;
 
 	/* close the old interface */
-	if (subs->interface >= 0 && subs->interface != fmt->iface) {
+	if (subs->interface >= 0 && (subs->interface != fmt->iface || subs->need_setup_fmt)) {
 		if (!subs->stream->chip->keep_iface) {
 			err = usb_set_interface(subs->dev, subs->interface, 0);
 			if (err < 0) {
@@ -528,6 +528,9 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 		subs->altset_idx = 0;
 	}
 
+	if (subs->need_setup_fmt)
+		subs->need_setup_fmt = false;
+
 	/* set interface */
 	if (iface->cur_altsetting != alts) {
 		err = snd_usb_select_mode_quirk(subs, fmt);
@@ -1728,6 +1731,13 @@ static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substrea
 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
 		subs->running = 0;
 		return 0;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		if (subs->stream->chip->setup_fmt_after_resume_quirk) {
+			stop_endpoints(subs, true);
+			subs->need_setup_fmt = true;
+			return 0;
+		}
+		break;
 	}
 
 	return -EINVAL;
@@ -1760,6 +1770,13 @@ static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream
 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
 		subs->running = 1;
 		return 0;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		if (subs->stream->chip->setup_fmt_after_resume_quirk) {
+			stop_endpoints(subs, true);
+			subs->need_setup_fmt = true;
+			return 0;
+		}
+		break;
 	}
 
 	return -EINVAL;