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authorClemens Ladisch <clemens@ladisch.de>2010-02-15 10:55:28 +0300
committerJaroslav Kysela <perex@perex.cz>2010-02-16 10:08:01 +0300
commitf167e1d073278fe231bbdd5d6c24fb9d091aa544 (patch)
tree98eea3aa4c5a559a608d375c4a8d269f333a5cb8
parent9d4c7464458770d309169f7a7ce1ea6f8a4a7de5 (diff)
downloadlinux-f167e1d073278fe231bbdd5d6c24fb9d091aa544.tar.xz
ALSA: usb-audio: reduce MIDI packet size to work around broken firmware
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> Cc: <stable@kernel.org> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
-rw-r--r--sound/usb/usbmidi.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 6e89b8368d9a..aae50df06232 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/usbmidi.c
@@ -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,