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authorDuncan Sands <baldrick@free.fr>2006-04-02 04:14:57 -0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2006-05-12 19:54:35 -0300
commit3203f94a25ea04b3052d22c7be9518538862d88f (patch)
tree5227daa69929027e83e49be2c169891fda76cfc5 /drivers
parentfaa88df860fdfad13afc99fc7201432f9263b3b5 (diff)
V4L/DVB (3704): Fix some errors on bttv_risc_overlay
There are tree mistakes on bttv_risc_overlay. 1) When skip_odd is true, the number of lines for which instructions are written is (height+1)/2, not height/2. 2) This occurs when clipping: the number of instruction bytes written can be as much as 8 + 12*nclips, not 8 + 8*nclips, as currently estimated. 3) Coverity check were wrong with nskips=0, since it means that it can clipped at most one line. Signed-off-by: Duncan Sands <baldrick@free.fr> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/media/video/bt8xx/bttv-risc.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/media/video/bt8xx/bttv-risc.c b/drivers/media/video/bt8xx/bttv-risc.c
index 16323a5d68a..afcfe71e379 100644
--- a/drivers/media/video/bt8xx/bttv-risc.c
+++ b/drivers/media/video/bt8xx/bttv-risc.c
@@ -233,7 +233,7 @@ bttv_risc_overlay(struct bttv *btv, struct btcx_riscmem *risc,
const struct bttv_format *fmt, struct bttv_overlay *ov,
int skip_even, int skip_odd)
{
- int instructions,rc,line,maxy,start,end,skip,nskips;
+ int dwords,rc,line,maxy,start,end,skip,nskips;
struct btcx_skiplist *skips;
u32 *rp,ri,ra;
u32 addr;
@@ -242,12 +242,12 @@ bttv_risc_overlay(struct bttv *btv, struct btcx_riscmem *risc,
if (NULL == (skips = kmalloc(sizeof(*skips) * ov->nclips,GFP_KERNEL)))
return -ENOMEM;
- /* estimate risc mem: worst case is (clip+1) * lines instructions
+ /* estimate risc mem: worst case is (1.5*clip+1) * lines instructions
+ sync + jump (all 2 dwords) */
- instructions = (ov->nclips + 1) *
- ((skip_even || skip_odd) ? ov->w.height>>1 : ov->w.height);
- instructions += 2;
- if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,instructions*8)) < 0) {
+ dwords = (3 * ov->nclips + 2) *
+ ((skip_even || skip_odd) ? (ov->w.height+1)>>1 : ov->w.height);
+ dwords += 4;
+ if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,dwords*4)) < 0) {
kfree(skips);
return rc;
}
@@ -276,8 +276,6 @@ bttv_risc_overlay(struct bttv *btv, struct btcx_riscmem *risc,
if (line > maxy)
btcx_calc_skips(line, ov->w.width, &maxy,
skips, &nskips, ov->clips, ov->nclips);
- else
- nskips = 0;
/* write out risc code */
for (start = 0, skip = 0; start < ov->w.width; start = end) {