From: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
The USB control messages require DMA to work. We cannot pass
a stack-allocated buffer, as it is not warranted that the
stack would be into a DMA enabled area.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
---
drivers/media/usb/s2255/s2255drv.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c
index c3a0e87066eb..f7bb78c1873c 100644
--- a/drivers/media/usb/s2255/s2255drv.c
+++ b/drivers/media/usb/s2255/s2255drv.c
@@ -1901,19 +1901,30 @@ static long s2255_vendor_req(struct s2255_dev *dev, unsigned char Request,
s32 TransferBufferLength, int bOut)
{
int r;
+ unsigned char *buf;
+
+ buf = kmalloc(TransferBufferLength, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
if (!bOut) {
r = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
Request,
USB_TYPE_VENDOR | USB_RECIP_DEVICE |
USB_DIR_IN,
- Value, Index, TransferBuffer,
+ Value, Index, buf,
TransferBufferLength, HZ * 5);
+
+ if (r >= 0)
+ memcpy(TransferBuffer, buf, TransferBufferLength);
} else {
+ memcpy(buf, TransferBuffer, TransferBufferLength);
r = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
Request, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
- Value, Index, TransferBuffer,
+ Value, Index, buf,
TransferBufferLength, HZ * 5);
}
+ kfree(buf);
return r;
}
--
2.7.4
--
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