Re: [PATCH 06/16] [media] ce6230: get rid of on-stack dma buffer
From: Antti Palosaari <hidden>
Date: 2011-03-18 17:20:45
Also in:
lkml
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<redacted>
Acked-by: Antti Palosaari <redacted> Reviewed-by: Antti Palosaari <redacted> Tested-by: Antti Palosaari <redacted> t. Antti
quoted hunk ↗ jump to hunk
--- 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; }
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