| Message ID | 1344958496-9373-23-git-send-email-t.stanislaws@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Tomasz, Thanks for the patch. On Tuesday 14 August 2012 17:34:52 Tomasz Stanislawski wrote: > From: Marek Szyprowski <m.szyprowski@samsung.com> > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > drivers/media/video/videobuf2-dma-contig.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/media/video/videobuf2-dma-contig.c > b/drivers/media/video/videobuf2-dma-contig.c index d44766e..11f4a46 100644 > --- a/drivers/media/video/videobuf2-dma-contig.c > +++ b/drivers/media/video/videobuf2-dma-contig.c > @@ -498,6 +498,16 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, > unsigned long vaddr, struct vm_area_struct *vma; > struct sg_table *sgt; > unsigned long contig_size; > + unsigned long dma_align = dma_get_cache_alignment(); > + > + /* > + * DMA transfers are not reliable to buffers which > + * are not cache line aligned! > + */ Are you scared of going near the 80 columns limit ? :-) > + if (vaddr & (dma_align - 1)) { You could use the IS_ALIGNED macro here, but that might just be nitpicking. > + pr_err("userptr must be aligned to %lu bytes\n", dma_align); > + return ERR_PTR(-EINVAL); > + } Shouldn't you also check that the size is a multiple of dma_align ? > buf = kzalloc(sizeof *buf, GFP_KERNEL); > if (!buf)
diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index d44766e..11f4a46 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -498,6 +498,16 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, struct vm_area_struct *vma; struct sg_table *sgt; unsigned long contig_size; + unsigned long dma_align = dma_get_cache_alignment(); + + /* + * DMA transfers are not reliable to buffers which + * are not cache line aligned! + */ + if (vaddr & (dma_align - 1)) { + pr_err("userptr must be aligned to %lu bytes\n", dma_align); + return ERR_PTR(-EINVAL); + } buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf)