[PATCH 1/2] drm/radeon: Don't use WC for VRAM if !RADEON_GEM_GTT_WC

[Koenig, Christian]

Am 09.09.2020 07:29 schrieb Huacai Chen <chenhc at lemote.com>:
Though RADEON_GEM_GTT_WC is initially used for GTT, but this flag is
bound to drm_arch_can_wc_memory(), and if arch doesn't support WC, then
VRAM should not use WC.

NAK, If System memory supports WC is completely independent from the VRAM BAR.

Christian.


Signed-off-by: Huacai Chen <chenhc at lemote.com>
---
 drivers/gpu/drm/radeon/radeon_object.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index f3dee01..07b82d9 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -117,10 +117,16 @@ void radeon_ttm_placement_from_domain(struct radeon_bo *rbo, u32 domain)
                                                      TTM_PL_FLAG_VRAM;
                 }

-               rbo->placements[c].fpfn = 0;
-               rbo->placements[c++].flags = TTM_PL_FLAG_WC |
-                                            TTM_PL_FLAG_UNCACHED |
-                                            TTM_PL_FLAG_VRAM;
+               if (rbo->flags & RADEON_GEM_GTT_WC) {
+                       rbo->placements[c].fpfn = 0;
+                       rbo->placements[c++].flags = TTM_PL_FLAG_WC |
+                                                    TTM_PL_FLAG_UNCACHED |
+                                                    TTM_PL_FLAG_VRAM;
+               } else {
+                       rbo->placements[c].fpfn = 0;
+                       rbo->placements[c++].flags = TTM_PL_FLAG_UNCACHED |
+                                                    TTM_PL_FLAG_VRAM;
+               }
         }

         if (domain & RADEON_GEM_DOMAIN_GTT) {
--
2.7.0


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