[PATCH 7/7] drm/i915: Merge FDI RX reg writes during training

[Keith Packard]

Need to turn on the error correction when enabling training or it
might not get enabled in time.

This seems to fix the FDI-B/FDI-C link training problem.

Signed-off-by: Keith Packard <keithp at keithp.com>
---
 drivers/gpu/drm/i915/intel_display.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c 
b/drivers/gpu/drm/i915/intel_display.c
index 754f10f..1d24d55 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2324,6 +2324,8 @@ static void intel_fdi_normal_train(struct drm_crtc *crtc)
                temp |= FDI_LINK_TRAIN_NONE | FDI_TX_ENHANCE_FRAME_ENABLE;
        }
        I915_WRITE(reg, temp);
+       POSTING_READ(reg);
+       udelay(100);

        reg = FDI_RX_CTL(pipe);
        temp = I915_READ(reg);
@@ -2334,16 +2336,15 @@ static void intel_fdi_normal_train(struct drm_crtc 
*crtc)
                temp &= ~FDI_LINK_TRAIN_NONE;
                temp |= FDI_LINK_TRAIN_NONE;
        }
+       /* IVB wants error correction enabled */
+       if (IS_IVYBRIDGE(dev))
+               temp |= FDI_FS_ERRC_ENABLE | FDI_FE_ERRC_ENABLE;
+
        I915_WRITE(reg, temp | FDI_RX_ENHANCE_FRAME_ENABLE);

        /* wait one idle pattern time */
        POSTING_READ(reg);
        udelay(1000);
-
-       /* IVB wants error correction enabled */
-       if (IS_IVYBRIDGE(dev))
-               I915_WRITE(reg, I915_READ(reg) | FDI_FS_ERRC_ENABLE |
-                          FDI_FE_ERRC_ENABLE);
 }

 static void cpt_phase_pointer_enable(struct drm_device *dev, int pipe)
-- 
1.7.10.4