Re: [PATCH 1/2] mips: Fix mips_dma_map_sg by using correct dma mapping function

From: Paul Burton
Date: Wed Jul 11 2018 - 12:03:50 EST


Hi Thomas,

On Wed, Jul 11, 2018 at 01:38:51PM +0200, Thomas Bogendoerfer wrote:
> sg list elements could cover more than one page of data. Therefore
> using plat_map_dma_mem_page() doesn't work for platforms, which have
> IOMMU functionality hidden behind plat_map_dma_XXX functions.
>
> Fixes: e36863a550da ("MIPS: HIGHMEM DMA on noncoherent MIPS32 processors")
> Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@xxxxxxx>
> ---
> arch/mips/mm/dma-default.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
> index f9fef0028ca2..2718185a3d38 100644
> --- a/arch/mips/mm/dma-default.c
> +++ b/arch/mips/mm/dma-default.c
> @@ -288,8 +288,8 @@ static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
> #ifdef CONFIG_NEED_SG_DMA_LENGTH
> sg->dma_length = sg->length;
> #endif
> - sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
> - sg->offset;
> + sg->dma_address = plat_map_dma_mem(dev, sg_virt(sg),
> + sg->length);
> }
>
> return nents;

This doesn't apply after Christoph's massive MIPS DMA cleanup which can
be found in mips-next (or linux-next). After this work we end up using
the generic dma_direct_map_sg() on most systems, and the code above has
been removed.

Thanks,
Paul