Commit b98ae272 authored Jan 04, 2013 by David Henningsson Committed by Takashi Iwai Jan 14, 2013

ALSA: usb - fix race in creation of M-Audio Fast track pro driver

A patch in the 3.2 kernel caused regression with hotplugging the
M-Audio Fast track pro, or sound after suspend. I don't have the
device so I haven't done a full analysis, but it seems userspace
(both udev and pulseaudio) got confused when a card was created,
immediately destroyed, and then created again.

However, at least one person in the bug report (martin djfun)
reports that this patch resolves the issue for him. It also leaves
a message in the log:
"snd-usb-audio: probe of 1-1.1:1.1 failed with error -5" which is
a bit misleading. It is better than non-working audio, but maybe
there's a more elegant solution?

BugLink: https://bugs.launchpad.net/bugs/1095315


Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent 31be5425

sound/usb/quirks.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -387,11 +387,13 @@ static int snd_usb_fasttrackpro_boot_quirk(struct usb_device *dev)
		* rules
		*/
		err = usb_driver_set_configuration(dev, 2);
		if (err < 0) {
		if (err < 0)
		snd_printdd("error usb_driver_set_configuration: %d\n",
		err);
		/* Always return an error, so that we stop creating a device
		that will just be destroyed and recreated with a new
		configuration */
		return -ENODEV;
		}
		} else
		snd_printk(KERN_INFO "usb-audio: Fast Track Pro config OK\n");