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usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize

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buflen by default (256) is smaller than wMaxPacketSize (512) in high-speed
devices.

That caused the OUT endpoint to freeze if the host send any data packet of
length greater than 256 bytes.

This is an example dump of what happended on that enpoint:
HOST:   [DATA][Length=260][...]
DEVICE: [NAK]
HOST:   [PING]
DEVICE: [NAK]
HOST:   [PING]
DEVICE: [NAK]
...
HOST:   [PING]
DEVICE: [NAK]

This patch fixes this problem by setting the minimum usb_request's buffer size
for the OUT endpoint as its wMaxPacketSize.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Felipe F. Tonello 2016-03-09 19:39:30 +00:00 committed by Felipe Balbi
parent 7e8ac87a44
commit 03d27ade49
1 changed files with 3 additions and 1 deletions
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4
drivers/usb/gadget/function/f_midi.c
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@ -360,7 +360,9 @@ static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
/* allocate a bunch of read buffers and queue them all at once. */
for (i = 0; i < midi->qlen && err == 0; i++) {
struct usb_request *req =
midi_alloc_ep_req(midi->out_ep, midi->buflen);
midi_alloc_ep_req(midi->out_ep,
max_t(unsigned, midi->buflen,
bulk_out_desc.wMaxPacketSize));
if (req == NULL)
return -ENOMEM;