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| author | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2016-10-10 11:17:15 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-10-14 12:52:29 -0300 |
| commit | b5f93cb5133d3ad517afef541502c6c9aecf8e5d (patch) | |
| tree | b2c45d247964f751c8818439ac3e3dd3177956f0 | |
| parent | db65c49e442cf9c9d9dc950f67daf109609f982a (diff) | |
| download | linux-b5f93cb5133d3ad517afef541502c6c9aecf8e5d.tar.gz | |
[media] stk-webcam: don't use stack for DMA
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@osg.samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
| -rw-r--r-- | drivers/media/usb/stkwebcam/stk-webcam.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c index db200c9d796d..22a9aae16291 100644 --- a/drivers/media/usb/stkwebcam/stk-webcam.c +++ b/drivers/media/usb/stkwebcam/stk-webcam.c @@ -147,20 +147,26 @@ int stk_camera_write_reg(struct stk_camera *dev, u16 index, u8 value) int stk_camera_read_reg(struct stk_camera *dev, u16 index, int *value) { struct usb_device *udev = dev->udev; + unsigned char *buf; int ret; + buf = kmalloc(sizeof(u8), GFP_KERNEL); + if (!buf) + return -ENOMEM; + ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), 0x00, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 0x00, index, - (u8 *) value, + buf, sizeof(u8), 500); - if (ret < 0) - return ret; - else - return 0; + if (ret >= 0) + memcpy(value, buf, sizeof(u8)); + + kfree(buf); + return ret; } static int stk_start_stream(struct stk_camera *dev) |