From: Ville Syrjälä <[email protected]>

Add a comment next to our WIZ hashing setup to remind people about the
link between WIZ hashing disable bit and PS/WM thread counts.

Suggested-by: Chris Wilson <[email protected]>
Signed-off-by: Ville Syrjälä <[email protected]>
---
 drivers/gpu/drm/i915/intel_pm.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index c3a1362..a3b61ca 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4647,6 +4647,10 @@ static void gen6_init_clock_gating(struct drm_device 
*dev)
        /*
         * BSpec recoomends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
+        *
+        * Note that PS/WM thread counts depend on the WIZ hashing
+        * disable bit, which we don't touch here, but it's good
+        * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN6_GT_MODE,
                   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
@@ -4830,6 +4834,10 @@ static void gen8_init_clock_gating(struct drm_device 
*dev)
        /*
         * BSpec recommends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
+        *
+        * Note that PS/WM thread counts depend on the WIZ hashing
+        * disable bit, which we don't touch here, but it's good
+        * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN7_GT_MODE,
                   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
@@ -4866,6 +4874,10 @@ static void haswell_init_clock_gating(struct drm_device 
*dev)
        /*
         * BSpec recommends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
+        *
+        * Note that PS/WM thread counts depend on the WIZ hashing
+        * disable bit, which we don't touch here, but it's good
+        * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN7_GT_MODE,
                   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
@@ -4954,6 +4966,10 @@ static void ivybridge_init_clock_gating(struct 
drm_device *dev)
        /*
         * BSpec recommends 8x4 when MSAA is used,
         * however in practice 16x4 seems fastest.
+        *
+        * Note that PS/WM thread counts depend on the WIZ hashing
+        * disable bit, which we don't touch here, but it's good
+        * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
         */
        I915_WRITE(GEN7_GT_MODE,
                   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
-- 
1.8.3.2

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