lkml.org 
[lkml]   [2011]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 06/16] [media] ce6230: get rid of on-stack dma buffer
On 03/15/2011 10:43 AM, Florian Mickler wrote:
> usb_control_msg initiates (and waits for completion of) a dma transfer using
> the supplied buffer. That buffer thus has to be seperately allocated on
> the heap.
>
> In lib/dma_debug.c the function check_for_stack even warns about it:
> WARNING: at lib/dma-debug.c:866 check_for_stack
>
> Note: This change is tested to compile only, as I don't have the hardware.
>
> Signed-off-by: Florian Mickler<florian@mickler.org>

Acked-by: Antti Palosaari <crope@iki.fi>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Tested-by: Antti Palosaari <crope@iki.fi>


t. Antti

> ---
> drivers/media/dvb/dvb-usb/ce6230.c | 11 +++++++++--
> 1 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/dvb/dvb-usb/ce6230.c b/drivers/media/dvb/dvb-usb/ce6230.c
> index 3df2045..6d1a304 100644
> --- a/drivers/media/dvb/dvb-usb/ce6230.c
> +++ b/drivers/media/dvb/dvb-usb/ce6230.c
> @@ -39,7 +39,7 @@ static int ce6230_rw_udev(struct usb_device *udev, struct req_t *req)
> u8 requesttype;
> u16 value;
> u16 index;
> - u8 buf[req->data_len];
> + u8 *buf;
>
> request = req->cmd;
> value = req->value;
> @@ -62,6 +62,12 @@ static int ce6230_rw_udev(struct usb_device *udev, struct req_t *req)
> goto error;
> }
>
> + buf = kmalloc(req->data_len, GFP_KERNEL);
> + if (!buf) {
> + ret = -ENOMEM;
> + goto error;
> + }
> +
> if (requesttype == (USB_TYPE_VENDOR | USB_DIR_OUT)) {
> /* write */
> memcpy(buf, req->data, req->data_len);
> @@ -74,7 +80,7 @@ static int ce6230_rw_udev(struct usb_device *udev, struct req_t *req)
> msleep(1); /* avoid I2C errors */
>
> ret = usb_control_msg(udev, pipe, request, requesttype, value, index,
> - buf, sizeof(buf), CE6230_USB_TIMEOUT);
> + buf, req->data_len, CE6230_USB_TIMEOUT);
>
> ce6230_debug_dump(request, requesttype, value, index, buf,
> req->data_len, deb_xfer);
> @@ -88,6 +94,7 @@ static int ce6230_rw_udev(struct usb_device *udev, struct req_t *req)
> if (!ret&& requesttype == (USB_TYPE_VENDOR | USB_DIR_IN))
> memcpy(req->data, buf, req->data_len);
>
> + kfree(buf);
> error:
> return ret;
> }


--
http://palosaari.fi/


\
 
 \ /
  Last update: 2011-03-18 18:23    [W:0.092 / U:9.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site