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    SubjectRe: [PATCH v2 -resend#1 1/1] V4L: videobuf, don't use dma addr as physical
    On Mon, Feb 28, 2011 at 10:37:02AM +0100, Jiri Slaby wrote:
    > mem->dma_handle is a dma address obtained by dma_alloc_coherent which
    > needn't be a physical address in presence of IOMMU. So ensure we are

    Can you add a comment why you are fixing it? Is there a bug report for this?
    Under what conditions did you expose this fault?

    You also might want to mention that "needn't be a physical address as
    a hardware IOMMU can (and most likely) will return a bus address where
    physical != bus address."

    Otherwise you can stick 'Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>'
    on it.

    > 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.
    >
    > Signed-off-by: Jiri Slaby <jslaby@suse.cz>
    > Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
    > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
    > ---
    > 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);
    > --
    > 1.7.4.1
    >


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