From: Johan Hovold johan@kernel.org
[ Upstream commit 8ed339f23d41e21660a389adf2e7b2966d457ff6 ]
The direction of the pipe argument must match the request-type direction bit or control requests may fail depending on the host-controller-driver implementation.
Control transfers without a data stage are treated as OUT requests by the USB stack and should be using usb_sndctrlpipe(). Failing to do so will now trigger a warning.
Fix the gl860_RTx() helper so that zero-length control reads fail with an error message instead. Note that there are no current callers that would trigger this.
Fixes: 4f7cb8837cec ("V4L/DVB (12954): gspca - gl860: Addition of GL860 based webcams") Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/usb/gspca/gl860/gl860.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/gspca/gl860/gl860.c b/drivers/media/usb/gspca/gl860/gl860.c index 262200af76a3..7da437e7785f 100644 --- a/drivers/media/usb/gspca/gl860/gl860.c +++ b/drivers/media/usb/gspca/gl860/gl860.c @@ -573,8 +573,8 @@ int gl860_RTx(struct gspca_dev *gspca_dev, len, 400 + 200 * (len > 1)); memcpy(pdata, gspca_dev->usb_buf, len); } else { - r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), - req, pref, val, index, NULL, len, 400); + gspca_err(gspca_dev, "zero-length read request\n"); + r = -EINVAL; } }