| Date | Fri, 12 Mar 2010 16:12:23 -0800 | From | Greg KH <> | Subject | [patch 045/123] ALSA: usb-audio: reduce MIDI packet size to work around broken firmware |
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2.6.33-stable review patch. If anyone has any objections, please let me know.
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From: Clemens Ladisch <clemens@ladisch.de>
commit f167e1d073278fe231bbdd5d6c24fb9d091aa544 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>
--- sound/usb/usbmidi.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)
--- a/sound/usb/usbmidi.c +++ b/sound/usb/usbmidi.c @@ -1162,10 +1162,22 @@ static int snd_usbmidi_out_endpoint_crea 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,
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