[PATCH] drm/radeon: Override fpfn for all VRAM placements in radeon_evict_flags

[Christian König]

Am 27.03.2017 um 02:58 schrieb Michel Dänzer:
> From: Michel Dänzer <michel.daenzer at amd.com>
>
> We were accidentally only overriding the first VRAM placement. For BOs
> with the RADEON_GEM_NO_CPU_ACCESS flag set,
> radeon_ttm_placement_from_domain creates a second VRAM placment with
> fpfn == 0. If VRAM is almost full, the first VRAM placement with
> fpfn > 0 may not work, but the second one with fpfn == 0 always will
> (the BO's current location trivially satisfies it). Because "moving"
> the BO to its current location puts it back on the LRU list, this
> results in an infinite loop.
>
> Fixes: 2a85aedd117c ("drm/radeon: Try evicting from CPU accessible to
>                        inaccessible VRAM first")
> Reported-by: Zachary Michaels <zmichaels at oblong.com>
> Reported-and-Tested-by: Julien Isorce <jisorce at oblong.com>
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com>

> ---
>   drivers/gpu/drm/radeon/radeon_ttm.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
> index 5c7cf644ba1d..37d68cd1f272 100644
> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> @@ -213,8 +213,8 @@ static void radeon_evict_flags(struct ttm_buffer_object *bo,
>   			rbo->placement.num_busy_placement = 0;
>   			for (i = 0; i < rbo->placement.num_placement; i++) {
>   				if (rbo->placements[i].flags & TTM_PL_FLAG_VRAM) {
> -					if (rbo->placements[0].fpfn < fpfn)
> -						rbo->placements[0].fpfn = fpfn;
> +					if (rbo->placements[i].fpfn < fpfn)
> +						rbo->placements[i].fpfn = fpfn;
>   				} else {
>   					rbo->placement.busy_placement =
>   						&rbo->placements[i];