On 03/01/2011 09:21 AM, Jiri Slaby wrote: > mem->dma_handle is a dma address obtained by dma_alloc_coherent which > needn't be a physical address as a hardware IOMMU can (and most > likely will) return a bus address where physical != bus address. So > ensure we are remapping (remap_pfn_range) the right page in > __videobuf_mmap_mapper by using virt_to_phys(mem->vaddr) and not > mem->dma_handle. > > While at it, use PFN_DOWN instead of explicit shift to obtain a frame > number. > > This was discovered by a random review of the code when looking for > something completely different. I'm not aware of any bug reports for > this. > > However it is a bug because many v4l drivers use this layer and have > no idea whether IOMMU is in the system and running or not. > > Signed-off-by: Jiri Slaby <[email protected]> > Cc: Mauro Carvalho Chehab <[email protected]> > Cc: Konrad Rzeszutek Wilk <[email protected]>
Ah, this is rather: Acked-by: Konrad Rzeszutek Wilk <[email protected]> > --- > > This is a version with updated changelog. > > drivers/media/video/videobuf-dma-contig.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/media/video/videobuf-dma-contig.c > b/drivers/media/video/videobuf-dma-contig.c > index c969111..19d3e4a 100644 > --- a/drivers/media/video/videobuf-dma-contig.c > +++ b/drivers/media/video/videobuf-dma-contig.c > @@ -300,7 +300,7 @@ static int __videobuf_mmap_mapper(struct videobuf_queue > *q, > > vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); > retval = remap_pfn_range(vma, vma->vm_start, > - mem->dma_handle >> PAGE_SHIFT, > + PFN_DOWN(virt_to_phys(mem->vaddr)) > size, vma->vm_page_prot); > if (retval) { > dev_err(q->dev, "mmap: remap failed with error %d. ", retval); -- js -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
