Messages in this thread Patch in this message | | | Date | Tue, 12 May 2009 09:55:08 +0200 | From | Clemens Ladisch <> | Subject | Re: bad endpoint address, MOTU FastLane |
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David Fries wrote: > usb_submit_urb returns -22 EINVAL invalid argument as it is trying to > submit an interrupt packet to what is registered as an isoc endpoint. > The second interface has the same end point addresses as the first. > Any suggestions on how to deal with this class of broken hardware? > > I:* If#= 0 Alt= 0 ... > E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=1ms > I:* If#= 1 Alt= 0 ... > E: Ad=81(I) Atr=01(Isoc) MxPS= 4 Ivl=1ms
AFAICS the USB core memorizes the descriptor belonging to a specific endpoint number whenever usb_set_interface() is called. In this case, the second interface is initialized later, so the second set of descriptors wins.
The driver could call usb_set_interface() again for the first interface so that the USB core takes notice of the first set of endpoints again. Please try the patch below.
I guess I'll have to write another quirk for this.
--- linux/sound/usb/usbmidi.c +++ linux/sound/usb/usbmidi.c @@ -1779,6 +1779,7 @@ err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints); break; case QUIRK_MIDI_RAW: + usb_set_interface(umidi->chip->dev, 0, 0); umidi->usb_protocol_ops = &snd_usbmidi_raw_ops; err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints); break;
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