[Intel-gfx] [PATCH] drm/i915: Return the correct score in i915_ppat_get()

[Zhi Wang]

The cache attribute of the required entry has to be the same with the
existing value. After this requirement is met, the futher comparison
should be performed. After this fix, the refined test case can pass.

v2:

- Refine the tittle and comments. (Rodrigo)

Fixes: 4395890a4855 ("drm/i915: Introduce private PAT management")
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Ben Widawsky <benjamin.widawsky at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 5923b51..636ad7d 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2965,7 +2965,7 @@ static unsigned int bdw_private_pat_match(u8 src, u8 dst)
 	};
 
 	/* Cache attribute has to be matched. */
-	if (GEN8_PPAT_GET_CA(src) == GEN8_PPAT_GET_CA(dst))
+	if (GEN8_PPAT_GET_CA(src) != GEN8_PPAT_GET_CA(dst))
 		return 0;
 
 	score |= CA_MATCH;
-- 
2.7.4