drm/i915: Implement WaVcpClkGateDisableForMediaReset:ctg, elk

Apparently we need to disable VCP unit clock gating around media reset
on g4x.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 39 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9b3681ee4a69..5122254e7213 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1835,6 +1835,10 @@ enum punit_power_well {
 #define VF_UNIT_CLOCK_GATE_DISABLE              (1 << 9)
 #define GS_UNIT_CLOCK_GATE_DISABLE              (1 << 7)
 #define CL_UNIT_CLOCK_GATE_DISABLE              (1 << 6)
+
+#define VDECCLK_GATE_D          0x620C          /* g4x only */
+#define  VCP_UNIT_CLOCK_GATE_DISABLE            (1 << 4)
+
 #define RAMCLK_GATE_D           0x6210          /* CRL only */
 #define DEUC                    0x6214          /* CRL only */
 
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 4ec192bc27ba..e7aa42d10f6c 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -988,6 +988,36 @@ static int i965_do_reset(struct drm_device *dev)
         return 0;
 }
 
+static int g4x_do_reset(struct drm_device *dev)
+{
+        struct drm_i915_private *dev_priv = dev->dev_private;
+        int ret;
+
+        pci_write_config_byte(dev->pdev, I965_GDRST,
+                              GRDOM_RENDER | GRDOM_RESET_ENABLE);
+        ret =  wait_for(i965_reset_complete(dev), 500);
+        if (ret)
+                return ret;
+
+        /* WaVcpClkGateDisableForMediaReset:ctg,elk */
+        I915_WRITE(VDECCLK_GATE_D, I915_READ(VDECCLK_GATE_D) | VCP_UNIT_CLOCK_GATE_DISABLE);
+        POSTING_READ(VDECCLK_GATE_D);
+
+        pci_write_config_byte(dev->pdev, I965_GDRST,
+                              GRDOM_MEDIA | GRDOM_RESET_ENABLE);
+        ret =  wait_for(i965_reset_complete(dev), 500);
+        if (ret)
+                return ret;
+
+        /* WaVcpClkGateDisableForMediaReset:ctg,elk */
+        I915_WRITE(VDECCLK_GATE_D, I915_READ(VDECCLK_GATE_D) & ~VCP_UNIT_CLOCK_GATE_DISABLE);
+        POSTING_READ(VDECCLK_GATE_D);
+
+        pci_write_config_byte(dev->pdev, I965_GDRST, 0);
+
+        return 0;
+}
+
 static int ironlake_do_reset(struct drm_device *dev)
 {
         struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1040,7 +1070,11 @@ int intel_gpu_reset(struct drm_device *dev)
         case 7:
         case 6: return gen6_do_reset(dev);
         case 5: return ironlake_do_reset(dev);
-        case 4: return i965_do_reset(dev);
+        case 4:
+                if (IS_G4X(dev))
+                        return g4x_do_reset(dev);
+                else
+                        return i965_do_reset(dev);
         default: return -ENODEV;
         }
 }