[Intel-gfx] [PATCH 18/25] drm/i915: Add WaDisableGafsUnitClkGating for skl and kbl

[Mika Kuoppala]

We need this gafs bit to be enabled for hw fix to
take effect. The spec doesn't give name to this bit so
name it by assuming it's function.

v2: name the bit (Ville)

References: HSD#2227156, HSD#2227050
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h         | 2 ++
 drivers/gpu/drm/i915/intel_ringbuffer.c | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 77f5edc5f915..313bb4b19d3d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6084,6 +6084,8 @@ enum skl_disp_power_wells {
 
 #define GEN9_CS_DEBUG_MODE1		_MMIO(0x20ec)
 #define GEN8_CS_CHICKEN1		_MMIO(0x2580)
+#define GEN8_CS_CHICKEN2		_MMIO(0x2194)
+# define GEN8_CS_GAFS_DISABLE_CLK_GATING (1 << 1)
 
 /* GEN7 chicken */
 #define GEN7_COMMON_SLICE_CHICKEN1		_MMIO(0x7010)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index a1488712628b..92404427c7f4 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1117,6 +1117,9 @@ static int skl_init_workarounds(struct intel_engine_cs *engine)
 			GEN7_HALF_SLICE_CHICKEN1,
 			GEN7_SBE_SS_CACHE_DISPATCH_PORT_SHARING_DISABLE);
 
+	/* WaDisableGafsUnitClkGating:skl */
+	WA_SET_BIT(GEN8_CS_CHICKEN2, GEN8_CS_GAFS_DISABLE_CLK_GATING);
+
 	/* WaDisableLSQCROPERFforOCL:skl */
 	ret = wa_ring_whitelist_reg(engine, GEN8_L3SQCREG4);
 	if (ret)
@@ -1218,6 +1221,9 @@ static int kbl_init_workarounds(struct intel_engine_cs *engine)
 		WA_SET_BIT_MASKED(COMMON_SLICE_CHICKEN2,
 				  GEN8_SBE_DISABLE_REPLAY_BUF_OPTIMIZATION);
 
+	/* WaDisableGafsUnitClkGating:kbl */
+	WA_SET_BIT(GEN8_CS_CHICKEN2, GEN8_CS_GAFS_DISABLE_CLK_GATING);
+
 	/* WaDisableLSQCROPERFforOCL:kbl */
 	ret = wa_ring_whitelist_reg(engine, GEN8_L3SQCREG4);
 	if (ret)
-- 
2.5.0