diff options
| author | Hans Verkuil <hans.verkuil@cisco.com> | 2014-09-04 18:26:52 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <m.chehab@samsung.com> | 2014-09-08 21:40:16 +0200 |
| commit | 947b38bb110c90e0bc93e7afe9ab6f007b6799a7 (patch) | |
| tree | ab0d4a0af53c7a308ac7d2d204cbaec920364b1d /drivers/media/pci | |
| parent | [media] cx23885: Add busy checks before changing formats (diff) | |
| download | linux-947b38bb110c90e0bc93e7afe9ab6f007b6799a7.tar.xz linux-947b38bb110c90e0bc93e7afe9ab6f007b6799a7.zip | |
[media] tw68: simplify tw68_buffer_count
The code to calculate the maximum number of buffers allowed in 4 MB
is 1) wrong if PAGE_SIZE != 4096 and 2) unnecessarily complex.
Fix and simplify the code.
Reported-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Diffstat (limited to 'drivers/media/pci')
| -rw-r--r-- | drivers/media/pci/tw68/tw68-video.c | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/drivers/media/pci/tw68/tw68-video.c b/drivers/media/pci/tw68/tw68-video.c index 66fae2345fdd..498ead9a956d 100644 --- a/drivers/media/pci/tw68/tw68-video.c +++ b/drivers/media/pci/tw68/tw68-video.c @@ -361,22 +361,13 @@ int tw68_video_start_dma(struct tw68_dev *dev, struct tw68_buf *buf) /* ------------------------------------------------------------------ */ -/* nr of (tw68-)pages for the given buffer size */ -static int tw68_buffer_pages(int size) -{ - size = PAGE_ALIGN(size); - size += PAGE_SIZE; /* for non-page-aligned buffers */ - size /= 4096; - return size; -} - /* calc max # of buffers from size (must not exceed the 4MB virtual * address space per DMA channel) */ static int tw68_buffer_count(unsigned int size, unsigned int count) { unsigned int maxcount; - maxcount = 1024 / tw68_buffer_pages(size); + maxcount = (4 * 1024 * 1024) / roundup(size, PAGE_SIZE); if (count > maxcount) count = maxcount; return count; |