re: V4L/DVB (13678): Add support for yet another DvbWorld, TeVii and Prof USB devices

re: V4L/DVB (13678): Add support for yet another DvbWorld, TeVii and Prof USB devices

[Dan Carpenter]

Hello Igor M. Liplianin,

The patch 141cc35e2d29: "V4L/DVB (13678): Add support for yet another
DvbWorld, TeVii and Prof USB devices" from Nov 27, 2009, leads to the
following Sparse warning:

	drivers/media/usb/dvb-usb/dw2102.c:288:36: error: bad constant
	expression

  CHECK   drivers/media/usb/dvb-usb/dw2102.c
drivers/media/usb/dvb-usb/dw2102.c:288:36: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:305:44: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:315:44: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:381:53: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:410:52: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:443:36: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:461:44: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:543:47: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:570:52: error: bad constant expression
drivers/media/usb/dvb-usb/dw2102.c:582:52: error: bad constant expression
  CC [M]  drivers/media/usb/dvb-usb/dw2102.o


   284          switch (num) {
   285          case 2: {
   286                  /* read */
   287                  /* first write first register number */
   288                  u8 ibuf[msg[1].len + 2], obuf[3];
                                ^^^^^^^^^^^^^^
The kernel has an 8k stack so the worry is that len could larger than
that.

   289                  obuf[0] = msg[0].addr << 1;
   290                  obuf[1] = msg[0].len;
   291                  obuf[2] = msg[0].buf[0];
   292                  dw210x_op_rw(d->udev, 0xc2, 0, 0,
   293                                  obuf, msg[0].len + 2, DW210X_WRITE_MSG);
   294                  /* second read registers */
   295                  dw210x_op_rw(d->udev, 0xc3, 0xd1 , 0,
   296                                  ibuf, msg[1].len + 2, DW210X_READ_MSG);
   297                  memcpy(msg[1].buf, ibuf + 2, msg[1].len);
   298  
   299                  break;
   300          }

regards,
dan carpenter