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@xxxxxxxxxxx>
---
drivers/media/dvb/dvb-usb/opera1.c | 31 ++++++++++++++++++++-----------
1 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/drivers/media/dvb/dvb-usb/opera1.c b/drivers/media/dvb/dvb-usb/opera1.c
index 1f1b7d6..2ca6e87 100644
--- a/drivers/media/dvb/dvb-usb/opera1.c
+++ b/drivers/media/dvb/dvb-usb/opera1.c
@@ -53,27 +53,36 @@ static int opera1_xilinx_rw(struct usb_device *dev, u8 request, u16 value,
u8 * data, u16 len, int flags)
{
int ret;
- u8 r;
- u8 u8buf[len];
-
+ u8 tmp;
+ u8 *buf;
unsigned int pipe = (flags == OPERA_READ_MSG) ?
usb_rcvctrlpipe(dev,0) : usb_sndctrlpipe(dev, 0);
u8 request_type = (flags == OPERA_READ_MSG) ? USB_DIR_IN : USB_DIR_OUT;
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
if (flags == OPERA_WRITE_MSG)
- memcpy(u8buf, data, len);
- ret =
- usb_control_msg(dev, pipe, request, request_type | USB_TYPE_VENDOR,
- value, 0x0, u8buf, len, 2000);
+ memcpy(buf, data, len);
+ ret = usb_control_msg(dev, pipe, request,
+ request_type | USB_TYPE_VENDOR, value, 0x0,
+ buf, len, 2000);
if (request == OPERA_TUNER_REQ) {
+ tmp = buf[0];
if (usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
- OPERA_TUNER_REQ, USB_DIR_IN | USB_TYPE_VENDOR,
- 0x01, 0x0, &r, 1, 2000)<1 || r!=0x08)
- return 0;
+ OPERA_TUNER_REQ, USB_DIR_IN | USB_TYPE_VENDOR,
+ 0x01, 0x0, buf, 1, 2000) < 1 || buf[0] != 0x08) {
+ ret = 0;
+ goto out;
+ }
+ buf[0] = tmp;
}
if (flags == OPERA_READ_MSG)
- memcpy(data, u8buf, len);
+ memcpy(data, buf, len);
+out:
+ kfree(buf);
return ret;
}
--
1.7.4.1
--
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