From 3203f94a25ea04b3052d22c7be9518538862d88f Mon Sep 17 00:00:00 2001 From: Duncan Sands Date: Sun, 2 Apr 2006 04:14:57 -0300 Subject: [PATCH] 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 Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/bt8xx/bttv-risc.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/media/video/bt8xx/bttv-risc.c b/drivers/media/video/bt8xx/bttv-risc.c index 16323a5d68ac..afcfe71e3792 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) {