V4L/DVB (10558): bttv: norm value should be unsigned

The norm value in the driver is an index into an array and the the driver
doesn't allow it to be negative or otherwise invalid.  It should be
unsigned but wasn't in all places.

Fix some structs and functions to have the norm be unsigned.  Get rid of
useless checks for "< 0".  Most of the driver code can't handle a norm
value that's out of range, so change some ">= BTTV_TVNORMS" checks to
BUG_ON().  There's no point in silently ignoring invalid driver state just
to crash because of it later.

Reported-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c
index c71f394fc0ea..4ec476a9c0e4 100644
--- a/drivers/media/video/bt8xx/bttv-driver.c
+++ b/drivers/media/video/bt8xx/bttv-driver.c
@@ -1277,7 +1277,7 @@ bttv_crop_calc_limits(struct bttv_crop *c)
 }
 
 static void
-bttv_crop_reset(struct bttv_crop *c, int norm)
+bttv_crop_reset(struct bttv_crop *c, unsigned int norm)
 {
         c->rect = bttv_tvnorms[norm].cropcap.defrect;
         bttv_crop_calc_limits(c);
@@ -1290,16 +1290,13 @@ set_tvnorm(struct bttv *btv, unsigned int norm)
         const struct bttv_tvnorm *tvnorm;
         v4l2_std_id id;
 
-        if (norm < 0 || norm >= BTTV_TVNORMS)
-                return -EINVAL;
+        BUG_ON(norm >= BTTV_TVNORMS);
+        BUG_ON(btv->tvnorm >= BTTV_TVNORMS);
 
         tvnorm = &bttv_tvnorms[norm];
 
-        if (btv->tvnorm < 0 ||
-            btv->tvnorm >= BTTV_TVNORMS ||
-            0 != memcmp(&bttv_tvnorms[btv->tvnorm].cropcap,
-                        &tvnorm->cropcap,
-                        sizeof (tvnorm->cropcap))) {
+        if (!memcmp(&bttv_tvnorms[btv->tvnorm].cropcap, &tvnorm->cropcap,
+                    sizeof (tvnorm->cropcap))) {
                 bttv_crop_reset(&btv->crop[0], norm);
                 btv->crop[1] = btv->crop[0]; /* current = default */