Am 22.02.2013 19:07, schrieb Kumar Amit Mehta:
> fix for instances of DMA buffer on stack(being passed to usb_control_msg) for
> the USB-DUXfast Board driver.
>
> Signed-off-by: Kumar Amit Mehta <gmate.amit@xxxxxxxxx>
> ---
> drivers/staging/comedi/drivers/usbduxfast.c | 30 ++++++++++++++++-----------
> 1 file changed, 18 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/staging/comedi/drivers/usbduxfast.c b/drivers/staging/comedi/drivers/usbduxfast.c
> index 4bf5dd0..1ba0e3d 100644
> --- a/drivers/staging/comedi/drivers/usbduxfast.c
> +++ b/drivers/staging/comedi/drivers/usbduxfast.c
> @@ -436,10 +436,14 @@ static void usbduxfastsub_ai_Irq(struct urb *urb)
> static int usbduxfastsub_start(struct usbduxfastsub_s *udfs)
> {
> int ret;
> - unsigned char local_transfer_buffer[16];
> + unsigned char *local_transfer_buffer;
> +
> + local_transfer_buffer = kmalloc(1, GFP_KERNEL);
> + if (!local_transfer_buffer)
> + return -ENOMEM;
>
> /* 7f92 to zero */
> - local_transfer_buffer[0] = 0;
> + *local_transfer_buffer = 0;
> /* bRequest, "Firmware" */
> ret = usb_control_msg(udfs->usbdev, usb_sndctrlpipe(udfs->usbdev, 0),
> USBDUXFASTSUB_FIRMWARE,
> @@ -450,22 +454,25 @@ static int usbduxfastsub_start(struct usbduxfastsub_s *udfs)
> local_transfer_buffer,
> 1, /* Length */
> EZTIMEOUT); /* Timeout */
> - if (ret < 0) {
> + if (ret < 0)
> dev_err(&udfs->interface->dev,
> "control msg failed (start)\n");
> - return ret;
> - }
>
> - return 0;
> + kfree(local_transfer_buffer);
> + return ret;
> }
>
> static int usbduxfastsub_stop(struct usbduxfastsub_s *udfs)
> {
> int ret;
> - unsigned char local_transfer_buffer[16];
> + unsigned char *local_transfer_buffer;
> +
> + local_transfer_buffer = kmalloc(1, GFP_KERNEL);
> + if (!local_transfer_buffer)
> + return -ENOMEM;
>
> /* 7f92 to one */
> - local_transfer_buffer[0] = 1;
> + *local_transfer_buffer = 1;
> /* bRequest, "Firmware" */
> ret = usb_control_msg(udfs->usbdev, usb_sndctrlpipe(udfs->usbdev, 0),
> USBDUXFASTSUB_FIRMWARE,
> @@ -474,13 +481,12 @@ static int usbduxfastsub_stop(struct usbduxfastsub_s *udfs)
> 0x0000, /* Index */
> local_transfer_buffer, 1, /* Length */
> EZTIMEOUT); /* Timeout */
> - if (ret < 0) {
> + if (ret < 0)
> dev_err(&udfs->interface->dev,
> "control msg failed (stop)\n");
> - return ret;
> - }
>
> - return 0;
> + kfree(local_transfer_buffer);
> + return ret;
> }
>
> static int usbduxfastsub_upload(struct usbduxfastsub_s *udfs,
mmh, it seems a bit overheat to alloc 1 byte.
Could one of the driver maintainers please comment
is that realy need ? or is it possible to pass one byte
in a register ? (aka char/int) without allocating ?
re,
wh
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