[alsa-devel] [PATCH] ALSA: usb-audio: set the interface format after resume on Dell WD19

[Hui Wang]

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 at canonical.com>
---
 sound/usb/card.h         |  1 +
 sound/usb/pcm.c          | 21 +++++++++++++++++++--
 sound/usb/quirks-table.h |  3 ++-
 sound/usb/quirks.c       | 11 +++++++++++
 sound/usb/usbaudio.h     |  3 ++-
 5 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/sound/usb/card.h b/sound/usb/card.h
index 2991b9986f66..395403a2d33f 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -145,6 +145,7 @@ struct snd_usb_substream {
 	struct snd_usb_endpoint *sync_endpoint;
 	unsigned long flags;
 	bool need_setup_ep;		/* (re)configure EP at prepare? */
+	bool need_setup_fmt;		/* (re)configure fmt after resume? */
 	unsigned int speed;		/* USB_SPEED_XXX */
 
 	u64 formats;			/* format bitmasks (all or'ed) */
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 8a52996041e9..4ac571b2e9a6 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -523,11 +523,11 @@ 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) {
@@ -541,6 +541,9 @@ 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);
@@ -1734,6 +1737,13 @@ 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;
@@ -1766,6 +1776,13 @@ 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;
diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index 70c338f3ae24..d187aa6d50db 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -3466,7 +3466,8 @@ AU0828_DEVICE(0x2040, 0x7270, "Hauppauge", "HVR-950Q"),
 		.vendor_name = "Dell",
 		.product_name = "WD19 Dock",
 		.profile_name = "Dell-WD15-Dock",
-		.ifnum = QUIRK_NO_INTERFACE
+		.ifnum = QUIRK_ANY_INTERFACE,
+		.type = QUIRK_SETUP_FMT_AFTER_RESUME
 	}
 },
 /* MOTU Microbook II */
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 349e1e52996d..a81c2066499f 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -508,6 +508,16 @@ static int create_standard_mixer_quirk(struct snd_usb_audio *chip,
 	return snd_usb_create_mixer(chip, quirk->ifnum, 0);
 }
 
+
+static int setup_fmt_after_resume_quirk(struct snd_usb_audio *chip,
+				       struct usb_interface *iface,
+				       struct usb_driver *driver,
+				       const struct snd_usb_audio_quirk *quirk)
+{
+	chip->setup_fmt_after_resume_quirk = 1;
+	return 1;	/* Continue with creating streams and mixer */
+}
+
 /*
  * audio-interface quirks
  *
@@ -546,6 +556,7 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip,
 		[QUIRK_AUDIO_EDIROL_UAXX] = create_uaxx_quirk,
 		[QUIRK_AUDIO_ALIGN_TRANSFER] = create_align_transfer_quirk,
 		[QUIRK_AUDIO_STANDARD_MIXER] = create_standard_mixer_quirk,
+		[QUIRK_SETUP_FMT_AFTER_RESUME] = setup_fmt_after_resume_quirk,
 	};
 
 	if (quirk->type < QUIRK_TYPE_COUNT) {
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index ff3cbf653de8..6fe3ab582ec6 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -33,7 +33,7 @@ struct snd_usb_audio {
 	wait_queue_head_t shutdown_wait;
 	unsigned int txfr_quirk:1; /* Subframe boundaries on transfers */
 	unsigned int tx_length_quirk:1; /* Put length specifier in transfers */
-	
+	unsigned int setup_fmt_after_resume_quirk:1; /* setup the format to interface after resume */
 	int num_interfaces;
 	int num_suspended_intf;
 	int sample_rate_read_error;
@@ -98,6 +98,7 @@ enum quirk_type {
 	QUIRK_AUDIO_EDIROL_UAXX,
 	QUIRK_AUDIO_ALIGN_TRANSFER,
 	QUIRK_AUDIO_STANDARD_MIXER,
+	QUIRK_SETUP_FMT_AFTER_RESUME,
 
 	QUIRK_TYPE_COUNT
 };
-- 
2.17.1