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authorClemens Ladisch <clemens@ladisch.de>2007-05-07 09:29:32 +0200
committerJaroslav Kysela <perex@suse.cz>2007-05-11 16:56:17 +0200
commit490cbd92ed4d9915b582f4e40c605eeb977e5d40 (patch)
treeafbe6759e98fe65ac4015869139c347b52ef8f44
parentd05cc104320210e1c38ff9675c5038cffb2d86dc (diff)
downloadlinux-490cbd92ed4d9915b582f4e40c605eeb977e5d40.tar.bz2
[ALSA] usb-audio: work around wrong wMaxPacketSize on ESI M4U
Add a workaround for the ESI M4U that claims to support 32-byte packets but ignores the remaining bytes of packets bigger than four bytes. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Jaroslav Kysela <perex@suse.cz>
-rw-r--r--sound/usb/usbmidi.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 911f4482b5e1..99295f9b7691 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/usbmidi.c
@@ -965,7 +965,11 @@ static int snd_usbmidi_out_endpoint_create(struct snd_usb_midi* umidi,
}
/* we never use interrupt output pipes */
pipe = usb_sndbulkpipe(umidi->chip->dev, ep_info->out_ep);
- ep->max_transfer = usb_maxpacket(umidi->chip->dev, pipe, 1);
+ if (umidi->chip->usb_id == USB_ID(0x0a92, 0x1020)) /* ESI M4U */
+ /* FIXME: we need more URBs to get reasonable bandwidth here: */
+ ep->max_transfer = 4;
+ else
+ ep->max_transfer = usb_maxpacket(umidi->chip->dev, pipe, 1);
buffer = usb_buffer_alloc(umidi->chip->dev, ep->max_transfer,
GFP_KERNEL, &ep->urb->transfer_dma);
if (!buffer) {