On 09/04/2014 04:46 PM, Mauro Carvalho Chehab wrote:
> This code implicitly assumes that pagesize is 4096, but this is
> not true on all archs, as the PAGE_SHIFT can be different than
> 12 on all those architectures: alpha, arc, arm64, cris, frv,
> hexagon,ia64, m68k, metag, microblaze, mips, openrisc, parisc,
> powerpc, sh, sparc and tile.
>
> The real constrant here seems to be to limit the buffer size to
> 4MB.
>
> So, fix the code to reflect that, in a way that it will keep
> working with differnt values for PAGE_SIZE.
While your fix is OK, I have a better patch that makes the code a lot more
readable. I'll post that soon.
Regards,
Hans
>
> Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
>
> diff --git a/drivers/media/pci/tw68/tw68-video.c b/drivers/media/pci/tw68/tw68-video.c
> index 4dd38578cf1b..66658accdca9 100644
> --- a/drivers/media/pci/tw68/tw68-video.c
> +++ b/drivers/media/pci/tw68/tw68-video.c
> @@ -366,7 +366,7 @@ static int tw68_buffer_pages(int size)
> {
> size = PAGE_ALIGN(size);
> size += PAGE_SIZE; /* for non-page-aligned buffers */
> - size /= 4096;
> + size /= PAGE_SIZE;
> return size;
> }
>
> @@ -376,7 +376,7 @@ static int tw68_buffer_count(unsigned int size, unsigned int count)
> {
> unsigned int maxcount;
>
> - maxcount = 1024 / tw68_buffer_pages(size);
> + maxcount = (4096 * 1024 / PAGE_SIZE) / tw68_buffer_pages(size);
> if (count > maxcount)
> count = maxcount;
> return count;
>
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
