TononixOS/ubports_kernel_google_msm
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

sound: usb-audio: make the MotU Fastlane work again

Browse Source 
Kernel 2.6.18 broke the MotU Fastlane, which uses duplicate endpoint
numbers in a manner that is not only illegal but also confuses the
kernel's endpoint descriptor caching mechanism.  To work around this, we
have to add a separate usb_set_interface() call to guide the USB core to
the correct descriptors.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Reported-and-tested-by: David Fries <david@fries.net>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Clemens Ladisch
2009-05-27 10:49:30 +02:00
committed by Takashi Iwai
parent 59a3759d0f
commit 55de5ef970
4 changed files with 14 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
sound/usb/usbmidi.c
View File

@@ -1778,8 +1778,18 @@ int snd_usb_create_midi_interface(struct snd_usb_audio* chip,
umidi->usb_protocol_ops = &snd_usbmidi_novation_ops;
err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
break;
case QUIRK_MIDI_RAW:
case QUIRK_MIDI_FASTLANE:
umidi->usb_protocol_ops = &snd_usbmidi_raw_ops;
/*
* Interface 1 contains isochronous endpoints, but with the same
* numbers as in interface 0. Since it is interface 1 that the
* USB core has most recently seen, these descriptors are now
* associated with the endpoint numbers. This will foul up our
* attempts to submit bulk/interrupt URBs to the endpoints in
* interface 0, so we have to make sure that the USB core looks
* again at interface 0 by calling usb_set_interface() on it.
*/
usb_set_interface(umidi->chip->dev, 0, 0);
err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
break;
case QUIRK_MIDI_EMAGIC: