drm/i915; Don't apply Ironlake FDI clock workaround to Sandybridge

Signed-off-by: Zhenyu Wang <zhenyu.z.wang@intel.com>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

2 files changed, 5 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2c2c19b6285e..90414ae86afc 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1321,6 +1321,7 @@ static inline void i915_write(struct drm_i915_private *dev_priv, u32 reg,
 
 #define INTEL_PCH_TYPE(dev) (((struct drm_i915_private *)(dev)->dev_private)->pch_type)
 #define HAS_PCH_CPT(dev) (INTEL_PCH_TYPE(dev) == PCH_CPT)
+#define HAS_PCH_IBX(dev) (INTEL_PCH_TYPE(dev) == PCH_IBX)
 
 #define PRIMARY_RINGBUFFER_SIZE         (128*1024)
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5e839c762456..48d8fd686ea9 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2212,9 +2212,10 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
         udelay(100);
 
         /* Ironlake workaround, disable clock pointer after downing FDI */
-        I915_WRITE(FDI_RX_CHICKEN(pipe),
-                   I915_READ(FDI_RX_CHICKEN(pipe) &
-                             ~FDI_RX_PHASE_SYNC_POINTER_ENABLE));
+        if (HAS_PCH_IBX(dev))
+                I915_WRITE(FDI_RX_CHICKEN(pipe),
+                           I915_READ(FDI_RX_CHICKEN(pipe) &
+                                     ~FDI_RX_PHASE_SYNC_POINTER_ENABLE));
 
         /* still set train pattern 1 */
         reg = FDI_TX_CTL(pipe);