Re: [PATCH 2/4] drm/ttm: introduce dma cache sync helpers

From: Thierry Reding
Date: Mon May 19 2014 - 04:36:22 EST


On Mon, May 19, 2014 at 04:10:56PM +0900, Alexandre Courbot wrote:
> From: Lucas Stach <dev@xxxxxxxxxx>
>
> On arches with non-coherent PCI,

I guess since this applies to gk20a

> we need to flush caches ourselfes at

"ourselves". Or perhaps even reword to something like: "..., caches need
to be flushed and invalidated explicitly", since dma_sync_for_cpu() does
invalidate rather than flush.

> the appropriate places. Introduce two small helpers to make things easy
> for TTM based drivers.
>
> Signed-off-by: Lucas Stach <dev@xxxxxxxxxx>
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
> ---
> drivers/gpu/drm/ttm/ttm_tt.c | 25 +++++++++++++++++++++++++
> include/drm/ttm/ttm_bo_driver.h | 28 ++++++++++++++++++++++++++++
> 2 files changed, 53 insertions(+)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
[...]
> +void ttm_dma_tt_cache_sync_for_device(struct ttm_dma_tt *ttm_dma,
> + struct device *dev)
> +{
> + int i;

This should probably be unsigned long to match the type of
ttm_dma->ttm.num_pages.

Thierry

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