Re: [PATCH v1 1/2] drivers: dma-coherent: Fix DMA coherent size for less than page

From: Greg Kroah-Hartman
Date: Tue Sep 27 2016 - 06:53:22 EST


On Thu, Sep 15, 2016 at 10:39:58AM +0100, Mark Craske wrote:
> From: "George G. Davis" <george_davis@xxxxxxxxxx>
>
> We fix a bug in dma_mmap_from_coherent() that appears when we map non page
> aligned DMA memory. It cuts off the non aligned part (this is different to
> dma_alloc_coherent() that always rounds up to full pages). So for mappings
> of less than a page we get -ENXIO as dma_mmap_from_coherent() assumes we
> want to map zero pages.
>
> Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
> Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
> Signed-off-by: Mark Craske <Mark_Craske@xxxxxxxxxx>
> ---
> drivers/base/dma-coherent.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
> index bdf28f7..abd83b7 100644
> --- a/drivers/base/dma-coherent.c
> +++ b/drivers/base/dma-coherent.c
> @@ -262,7 +262,7 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
> unsigned long off = vma->vm_pgoff;
> int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;
> int user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
> - int count = size >> PAGE_SHIFT;
> + int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
>
> *ret = -ENXIO;
> if (off < count && user_count <= count - off) {
> --
> 1.7.9.5
>

Doesn't apply to my tree (or linux-next) :(

Can you refresh this series and resend?

thanks,

greg k-h