From: Stefan Hajnoczi Date: Wed, 23 Nov 2011 08:20:44 +0000 Subject: [004/106] staging: line6: use smallest iso ep packet size commit 3b08db37cb04a80dccac8c2d7b03690b5f179487 upstream. The POD HD300 isochronous endpoints have different max packet sizes for read and write. Using the read endpoint max packet size may be too large for the write endpoint. Instead we should use the minimum of both endpoints to be sure the size is acceptable. In theory we could decouple read and write packet sizes but the driver currently uses a single size which I chose not to mess with since other features like software monitoring may depend on a single packet size for both endpoints. Signed-off-by: Stefan Hajnoczi Signed-off-by: Greg Kroah-Hartman --- drivers/staging/line6/pcm.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/staging/line6/pcm.c b/drivers/staging/line6/pcm.c index f56c642..ae98434 100644 --- a/drivers/staging/line6/pcm.c +++ b/drivers/staging/line6/pcm.c @@ -452,9 +452,14 @@ int line6_init_pcm(struct usb_line6 *line6, line6pcm->line6 = line6; line6pcm->ep_audio_read = ep_read; line6pcm->ep_audio_write = ep_write; - line6pcm->max_packet_size = usb_maxpacket(line6->usbdev, - usb_rcvintpipe(line6->usbdev, - ep_read), 0); + + /* Read and write buffers are sized identically, so choose minimum */ + line6pcm->max_packet_size = min( + usb_maxpacket(line6->usbdev, + usb_rcvisocpipe(line6->usbdev, ep_read), 0), + usb_maxpacket(line6->usbdev, + usb_sndisocpipe(line6->usbdev, ep_write), 1)); + line6pcm->properties = properties; line6->line6pcm = line6pcm;