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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2015-08-14 17:19:43 -0500
committerTakashi Iwai <tiwai@suse.de>2015-08-16 08:48:47 +0200
commit395ae54bd8775508a9616817188cabbcd6f53260 (patch)
treede6bdb631be10f249c341ee86c056d6a00ae6f97 /sound/usb/pcm.c
parent630184477e7eccb2b31ee4c20b6905ca5fa4b3a8 (diff)
downloadlinux-395ae54bd8775508a9616817188cabbcd6f53260.tar.bz2
ALSA: usb: handle descriptor with SYNC_NONE illegal value
The M-Audio Transit exposes an interface with a SYNC_NONE attribute. This is not a valid value according to the USB audio classspec. However there is a sync endpoint associated to this record. Changing the logic to try to use this sync endpoint allows for seamless transitions between altset 2 and altset 3. If any errors happen, the behavior remains the same. $ more /proc/asound/card1/stream0 M-Audio Transit USB at usb-0000:00:14.0-2, full speed : USB Audio Playback: Status: Stop Interface 1 Altset 1 Format: S24_3LE Channels: 2 Endpoint: 3 OUT (ADAPTIVE) Rates: 48001 - 96000 (continuous) Interface 1 Altset 2 Format: S24_3LE Channels: 2 Endpoint: 3 OUT (NONE) Rates: 8000 - 48000 (continuous) Interface 1 Altset 3 Format: S16_LE Channels: 2 Endpoint: 3 OUT (ASYNC) Rates: 8000 - 48000 (continuous) Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/pcm.c')
-rw-r--r--sound/usb/pcm.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 7fb17c8eb49d..30797269d5aa 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -412,10 +412,17 @@ static int set_sync_endpoint(struct snd_usb_substream *subs,
if (altsd->bNumEndpoints < 2)
return 0;
- if ((is_playback && attr != USB_ENDPOINT_SYNC_ASYNC) ||
+ if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
+ attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
(!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
return 0;
+ /*
+ * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
+ * if we don't find a sync endpoint, as on M-Audio Transit. In case of
+ * error fall back to SYNC mode and don't create sync endpoint
+ */
+
/* check sync-pipe endpoint */
/* ... and check descriptor size before accessing bSynchAddress
because there is a version of the SB Audigy 2 NX firmware lacking
@@ -429,6 +436,8 @@ static int set_sync_endpoint(struct snd_usb_substream *subs,
get_endpoint(alts, 1)->bmAttributes,
get_endpoint(alts, 1)->bLength,
get_endpoint(alts, 1)->bSynchAddress);
+ if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
+ return 0;
return -EINVAL;
}
ep = get_endpoint(alts, 1)->bEndpointAddress;
@@ -439,6 +448,8 @@ static int set_sync_endpoint(struct snd_usb_substream *subs,
"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
fmt->iface, fmt->altsetting,
is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
+ if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
+ return 0;
return -EINVAL;
}
@@ -450,8 +461,11 @@ static int set_sync_endpoint(struct snd_usb_substream *subs,
implicit_fb ?
SND_USB_ENDPOINT_TYPE_DATA :
SND_USB_ENDPOINT_TYPE_SYNC);
- if (!subs->sync_endpoint)
+ if (!subs->sync_endpoint) {
+ if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
+ return 0;
return -EINVAL;
+ }
subs->data_endpoint->sync_master = subs->sync_endpoint;