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[media] stk-webcam: don't use stack for DMA

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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>
This commit is contained in:
Mauro Carvalho Chehab 2016-10-10 11:17:15 -03:00 committed by Mauro Carvalho Chehab
parent db65c49e44
commit b5f93cb513
1 changed files with 11 additions and 5 deletions
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16
drivers/media/usb/stkwebcam/stk-webcam.c
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@ -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) int stk_camera_read_reg(struct stk_camera *dev, u16 index, int *value)
{ {
struct usb_device *udev = dev->udev; struct usb_device *udev = dev->udev;
unsigned char *buf;
int ret; int ret;
buf = kmalloc(sizeof(u8), GFP_KERNEL);
if (!buf)
return -ENOMEM;
ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
0x00, 0x00,
USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
0x00, 0x00,
index, index,
(u8 *) value, buf,
sizeof(u8), sizeof(u8),
500); 500);
if (ret < 0) if (ret >= 0)
return ret; memcpy(value, buf, sizeof(u8));
else
return 0; kfree(buf);
return ret;
} }
static int stk_start_stream(struct stk_camera *dev) static int stk_start_stream(struct stk_camera *dev)