This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: work around Android accessory firmware bug
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-usb-audio-work-around-android-accessory-firmware-bug.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 342cda29343a6272c630f94ed56810a76740251b Mon Sep 17 00:00:00 2001
From: Clemens Ladisch <clemens@xxxxxxxxxx>
Date: Sat, 15 Jun 2013 11:21:09 +0200
Subject: ALSA: usb-audio: work around Android accessory firmware bug
From: Clemens Ladisch <clemens@xxxxxxxxxx>
commit 342cda29343a6272c630f94ed56810a76740251b upstream.
When the Android firmware enables the audio interfaces in accessory
mode, it always declares in the control interface's baInterfaceNr array
that interfaces 0 and 1 belong to the audio function. However, the
accessory interface itself, if also enabled, already is at index 0 and
shifts the actual audio interface numbers to 1 and 2, which prevents the
PCM streaming interface from being seen by the host driver.
To get the PCM interface interface to work, detect when the descriptors
point to the (for this driver useless) accessory interface, and redirect
to the correct one.
Reported-by: Jeremy Rosen <jeremy.rosen@xxxxxxxxxxx>
Tested-by: Jeremy Rosen <jeremy.rosen@xxxxxxxxxxx>
Signed-off-by: Clemens Ladisch <clemens@xxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/card.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -148,14 +148,32 @@ static int snd_usb_create_stream(struct
return -EINVAL;
}
+ alts = &iface->altsetting[0];
+ altsd = get_iface_desc(alts);
+
+ /*
+ * Android with both accessory and audio interfaces enabled gets the
+ * interface numbers wrong.
+ */
+ if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
+ chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
+ interface == 0 &&
+ altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
+ altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
+ interface = 2;
+ iface = usb_ifnum_to_if(dev, interface);
+ if (!iface)
+ return -EINVAL;
+ alts = &iface->altsetting[0];
+ altsd = get_iface_desc(alts);
+ }
+
if (usb_interface_claimed(iface)) {
snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
dev->devnum, ctrlif, interface);
return -EINVAL;
}
- alts = &iface->altsetting[0];
- altsd = get_iface_desc(alts);
if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
Patches currently in stable-queue which might be from clemens@xxxxxxxxxx are
queue-3.0/alsa-usb-audio-work-around-android-accessory-firmware-bug.patch
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