drm/i915: disable RCBP and VDS unit clock gating on SNB and VLV
The RCBP workaround still applies on these chips, and we need VDS as well.
v2: remove MB boot fetch that snuck in (Daniel)
add workaround tags to comments for easier internal tracking (Daniel)
v3: only apply RCPB and VDS on SNB and VLV, IVB doesn't need them (Eugeni)
References: https://bugs.freedesktop.org/show_bug.cgi?id=50251
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 404b474..54c5e53 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3330,8 +3330,12 @@
*
* According to the spec, bit 11 (RCCUNIT) must also be set,
* but we didn't debug actual testcases to find it out.
+ *
+ * Also apply WaDisableVDSUnitClockGating and
+ * WaDisableRCPBUnitClockGating.
*/
I915_WRITE(GEN6_UCGCTL2,
+ GEN7_VDSUNIT_CLOCK_GATE_DISABLE |
GEN6_RCPBUNIT_CLOCK_GATE_DISABLE |
GEN6_RCCUNIT_CLOCK_GATE_DISABLE);
@@ -3392,11 +3396,6 @@
I915_WRITE(WM2_LP_ILK, 0);
I915_WRITE(WM1_LP_ILK, 0);
- /* According to the spec, bit 13 (RCZUNIT) must be set on IVB.
- * This implements the WaDisableRCZUnitClockGating workaround.
- */
- I915_WRITE(GEN6_UCGCTL2, GEN6_RCZUNIT_CLOCK_GATE_DISABLE);
-
I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE);
I915_WRITE(IVB_CHICKEN3,
@@ -3413,6 +3412,23 @@
I915_WRITE(GEN7_L3_CHICKEN_MODE_REGISTER,
GEN7_WA_L3_CHICKEN_MODE);
+ /* According to the BSpec vol1g, bit 12 (RCPBUNIT) clock
+ * gating disable must be set. Failure to set it results in
+ * flickering pixels due to Z write ordering failures after
+ * some amount of runtime in the Mesa "fire" demo, and Unigine
+ * Sanctuary and Tropics, and apparently anything else with
+ * alpha test or pixel discard.
+ *
+ * According to the spec, bit 11 (RCCUNIT) must also be set,
+ * but we didn't debug actual testcases to find it out.
+ *
+ * According to the spec, bit 13 (RCZUNIT) must be set on IVB.
+ * This implements the WaDisableRCZUnitClockGating workaround.
+ */
+ I915_WRITE(GEN6_UCGCTL2,
+ GEN6_RCZUNIT_CLOCK_GATE_DISABLE |
+ GEN6_RCCUNIT_CLOCK_GATE_DISABLE);
+
/* This is required by WaCatErrorRejectionIssue */
I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
@@ -3449,11 +3465,6 @@
I915_WRITE(WM2_LP_ILK, 0);
I915_WRITE(WM1_LP_ILK, 0);
- /* According to the spec, bit 13 (RCZUNIT) must be set on IVB.
- * This implements the WaDisableRCZUnitClockGating workaround.
- */
- I915_WRITE(GEN6_UCGCTL2, GEN6_RCZUNIT_CLOCK_GATE_DISABLE);
-
I915_WRITE(ILK_DSPCLK_GATE, IVB_VRHUNIT_CLK_GATE);
I915_WRITE(IVB_CHICKEN3,
@@ -3473,6 +3484,29 @@
I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB);
+
+ /* According to the BSpec vol1g, bit 12 (RCPBUNIT) clock
+ * gating disable must be set. Failure to set it results in
+ * flickering pixels due to Z write ordering failures after
+ * some amount of runtime in the Mesa "fire" demo, and Unigine
+ * Sanctuary and Tropics, and apparently anything else with
+ * alpha test or pixel discard.
+ *
+ * According to the spec, bit 11 (RCCUNIT) must also be set,
+ * but we didn't debug actual testcases to find it out.
+ *
+ * According to the spec, bit 13 (RCZUNIT) must be set on IVB.
+ * This implements the WaDisableRCZUnitClockGating workaround.
+ *
+ * Also apply WaDisableVDSUnitClockGating and
+ * WaDisableRCPBUnitClockGating.
+ */
+ I915_WRITE(GEN6_UCGCTL2,
+ GEN7_VDSUNIT_CLOCK_GATE_DISABLE |
+ GEN6_RCZUNIT_CLOCK_GATE_DISABLE |
+ GEN6_RCPBUNIT_CLOCK_GATE_DISABLE |
+ GEN6_RCCUNIT_CLOCK_GATE_DISABLE);
+
for_each_pipe(pipe) {
I915_WRITE(DSPCNTR(pipe),
I915_READ(DSPCNTR(pipe)) |