[PATCH 2/3] drm/radeon: Restore GART table contents after pinning it in VRAM v3

[Christian König]

Am 22.01.2015 um 10:58 schrieb Michel Dänzer:
> From: Michel Dänzer <michel.daenzer at amd.com>
>
> The GART table BO has to be moved out of VRAM for suspend/resume. Any
> updates to the GART table during that time were silently dropped without
> this change. This caused GPU lockups on resume in some cases, see the bug
> reports referenced below.
>
> This might also make GPU reset more robust in some cases, as we no longer
> rely on the GART table in VRAM being preserved across the GPU
> lockup/reset.
>
> v2: Add logic to radeon_gart_table_vram_pin directly instead of
>      reinstating radeon_gart_restore
> v3: Move code after assignment of rdev->gart.table_addr so that the GART
>      TLB flush can work as intended, add code comment explaining why we're
>      doing this
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85204
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86267
> Cc: stable at vger.kernel.org
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>

This one and the two others in the series are Reviewed-by: Christian 
König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/radeon/radeon_gart.c | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
> index a530932..c7be612 100644
> --- a/drivers/gpu/drm/radeon/radeon_gart.c
> +++ b/drivers/gpu/drm/radeon/radeon_gart.c
> @@ -165,6 +165,19 @@ int radeon_gart_table_vram_pin(struct radeon_device *rdev)
>   		radeon_bo_unpin(rdev->gart.robj);
>   	radeon_bo_unreserve(rdev->gart.robj);
>   	rdev->gart.table_addr = gpu_addr;
> +
> +	if (!r) {
> +		int i;
> +
> +		/* We might have dropped some GART table updates while it wasn't
> +		 * mapped, restore all entries
> +		 */
> +		for (i = 0; i < rdev->gart.num_gpu_pages; i++)
> +			radeon_gart_set_page(rdev, i, rdev->gart.pages_entry[i]);
> +		mb();
> +		radeon_gart_tlb_flush(rdev);
> +	}
> +
>   	return r;
>   }
>