Re: [alsa-devel] [PATCH] ALSA: usb-audio: fix PCM device order

Ping? This patch never got any feedback, and yesterday another user complained on PulseAudio bug tracker that Audinst HUD-mx2 doesn't work out of the box, because by default hw:x,0 is used when hw:x,1 is the pcm that works.

-- Tanu

On Fri, 2017-08-11 at 02:36 +0300, Alexander Tsoy wrote:

Some cards have alternate setting with non-PCM format as the first altsetting in the interface descriptors. This confuses userspace, since alsa-lib uses device 0 by default. So lets parse interfaces in two steps:

1. Parse altsettings with PCM formats.
2. Parse altsettings with non-PCM formats.

This fixes at least following cards:

• Audinst HUD-mx2
• Audinst HUD-mini

Signed-off-by: Alexander Tsoy alexander@tsoy.me

sound/usb/stream.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/sound/usb/stream.c b/sound/usb/stream.c index 8e9548bc1f1a..b2ebeae91396 100644 --- a/sound/usb/stream.c +++ b/sound/usb/stream.c @@ -477,7 +477,8 @@ static struct uac2_output_terminal_descriptor * return NULL; }

-int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no) +static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no,

• 		           bool *has_non_pcm, bool non_pcm)
  

{ struct usb_device *dev; struct usb_interface *iface; @@ -634,6 +635,10 @@ int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no) iface_no, altno); continue; }

• if (fmt->bFormatType != UAC_FORMAT_TYPE_I)
  

• 	*has_non_pcm = true;
  

• if ((fmt->bFormatType == UAC_FORMAT_TYPE_I) == non_pcm)
  

• 	continue;
  

  if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8)) || ((protocol == UAC_VERSION_2) && (fmt->bLength < 6))) { dev_err(&dev->dev,

@@ -740,3 +745,23 @@ int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no) return 0; }

+int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no) +{

• int err;
• bool has_non_pcm = false;
• /* parse PCM formats */
• err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
• if (err < 0)

• return err;
  

• if (has_non_pcm) {

• /* parse non-PCM formats */
  

• err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
  

• if (err < 0)
  

• 	return err;
  

• }
• return 0;

+}