Re: [PATCH 5.2 073/131] dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device

[Sasha Levin]

On Mon, Aug 05, 2019 at 03:02:40PM +0200, Greg Kroah-Hartman wrote:
> [ Upstream commit 449fa54d6815be8c2c1f68fa9dbbae9384a7c03e ]
>
> dma_map_sg() may use swiotlb buffer when the kernel command line includes
> "swiotlb=force" or the dma_addr is out of dev->dma_mask range.  After
> DMA complete the memory moving from device to memory, then user call
> dma_sync_sg_for_cpu() to sync with DMA buffer, and copy the original
> virtual buffer to other space.
>
> So dma_direct_sync_sg_for_cpu() should use swiotlb physical addr, not
> the original physical addr from sg_phys(sg).
>
> dma_direct_sync_sg_for_device() also has the same issue, correct it as
> well.
>
> Fixes: 55897af63091("dma-direct: merge swiotlb_dma_ops into the dma_direct code")
> Signed-off-by: Fugang Duan <fugang.duan@xxxxxxx>
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

I'm going to drop this one. There's a fix to it upstream, but the fix
also seems to want 0036bc73ccbe ("drm/msm: stop abusing dma_map/unmap for
cache") which we're not taking, so I'm just going to drop this one as
well.

If someone wants it in the stable trees, please send a tested backport.

--
Thanks,
Sasha