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authorClemens Ladisch <clemens@ladisch.de>2009-05-27 10:49:30 +0200
committerTakashi Iwai <tiwai@suse.de>2009-05-27 11:25:33 +0200
commit55de5ef970c680d8d75f2a9aa7e4f172140dbd9c (patch)
tree3fed0a032ccc3050ceacbe4f230d1c02cd122f1c /sound/usb/usbmidi.c
parent59a3759d0fe8d969888c741bb33f4946e4d3750d (diff)
sound: usb-audio: make the MotU Fastlane work again
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>
Diffstat (limited to 'sound/usb/usbmidi.c')
-rw-r--r--sound/usb/usbmidi.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 26bad373fe6..2fb35cc22a3 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/usbmidi.c
@@ -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: