[PATCH] ALSA: usb-audio: fix control-request direction

Johan Hovold johan at kernel.org
Fri May 21 15:37:42 CEST 2021


The direction of the pipe argument must match the request-type direction
bit or control requests may fail depending on the host-controller-driver
implementation.

Fix the UAC2_CS_CUR request which erroneously used usb_sndctrlpipe().

Fixes: 93db51d06b32 ("ALSA: usb-audio: Check valid altsetting at parsing rates for UAC2/3")
Cc: stable at vger.kernel.org      # 5.10
Signed-off-by: Johan Hovold <johan at kernel.org>
---

There's a related bug in sound/usb/mixer_scarlett_gen2.c, which
Geoffrey reported and said he was preparing a patch for here:

	https://lore.kernel.org/r/20210520180819.GA95348@m.b4.vu

Johan


 sound/usb/format.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/usb/format.c b/sound/usb/format.c
index e6ff317a6785..2287f8c65315 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -436,7 +436,7 @@ static bool check_valid_altsetting_v2v3(struct snd_usb_audio *chip, int iface,
 	if (snd_BUG_ON(altsetting >= 64 - 8))
 		return false;
 
-	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
+	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 			      UAC2_AS_VAL_ALT_SETTINGS << 8,
 			      iface, &raw_data, sizeof(raw_data));
-- 
2.26.3



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