diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/media/video/cx88/cx88-core.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/media/video/cx88/cx88-core.c b/drivers/media/video/cx88/cx88-core.c index 2c3d9f1999b..e1092d5d462 100644 --- a/drivers/media/video/cx88/cx88-core.c +++ b/drivers/media/video/cx88/cx88-core.c @@ -146,9 +146,11 @@ int cx88_risc_buffer(struct pci_dev *pci, struct btcx_riscmem *risc, fields++; /* estimate risc mem: worst case is one write per page border + - one write per scan line + syncs + jump (all 2 dwords) */ - instructions = (bpl * lines * fields) / PAGE_SIZE + lines * fields; - instructions += 3 + 4; + one write per scan line + syncs + jump (all 2 dwords). Padding + can cause next bpl to start close to a page border. First DMA + region may be smaller than PAGE_SIZE */ + instructions = fields * (1 + ((bpl + padding) * lines) / PAGE_SIZE + lines); + instructions += 2; if ((rc = btcx_riscmem_alloc(pci,risc,instructions*8)) < 0) return rc; @@ -176,9 +178,11 @@ int cx88_risc_databuffer(struct pci_dev *pci, struct btcx_riscmem *risc, int rc; /* estimate risc mem: worst case is one write per page border + - one write per scan line + syncs + jump (all 2 dwords) */ - instructions = (bpl * lines) / PAGE_SIZE + lines; - instructions += 3 + 4; + one write per scan line + syncs + jump (all 2 dwords). Here + there is no padding and no sync. First DMA region may be smaller + than PAGE_SIZE */ + instructions = 1 + (bpl * lines) / PAGE_SIZE + lines; + instructions += 1; if ((rc = btcx_riscmem_alloc(pci,risc,instructions*8)) < 0) return rc; |