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ALSA: usb-audio: reduce MIDI packet size to work around broken firmware

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commit f167e1d073 upstream.

Extend the list of devices whose firmware does not expect more than one
USB MIDI packet in one USB packet.

bug report: https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3752

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Clemens Ladisch
2010-02-15 08:55:28 +01:00
committed by Greg Kroah-Hartman
parent 616b05819b
commit c7a4ea295b
1 changed files with 15 additions and 3 deletions
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18
sound/usb/usbmidi.c
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@@ -1162,10 +1162,22 @@ static int snd_usbmidi_out_endpoint_create(struct snd_usb_midi* umidi,
pipe = usb_sndintpipe(umidi->dev, ep_info->out_ep);
else
pipe = usb_sndbulkpipe(umidi->dev, ep_info->out_ep);
if (umidi->usb_id == USB_ID(0x0a92, 0x1020)) /* ESI M4U */
ep->max_transfer = 4;
else
switch (umidi->usb_id) {
default:
ep->max_transfer = usb_maxpacket(umidi->dev, pipe, 1);
break;
/*
* Various chips declare a packet size larger than 4 bytes, but
* do not actually work with larger packets:
*/
case USB_ID(0x0a92, 0x1020): /* ESI M4U */
case USB_ID(0x1430, 0x474b): /* RedOctane GH MIDI INTERFACE */
case USB_ID(0x15ca, 0x0101): /* Textech USB Midi Cable */
case USB_ID(0x15ca, 0x1806): /* Textech USB Midi Cable */
case USB_ID(0x1a86, 0x752d): /* QinHeng CH345 "USB2.0-MIDI" */
ep->max_transfer = 4;
break;
}
for (i = 0; i < OUTPUT_URBS; ++i) {
buffer = usb_buffer_alloc(umidi->dev,
ep->max_transfer, GFP_KERNEL,