[Intel-gfx] [PATCH 2/2] drm/i915: use SNB A step FDI values on A step CPUs

[Jesse Barnes]

More of an example of where to use the stepping macro than anything
else.  I think these early steppings never went outside of Intel.

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_display.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bdb4624..828bac5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2883,6 +2883,13 @@ static void ironlake_fdi_link_train(struct drm_crtc *crtc)
 
 }
 
+static const int snb_a_fdi_train_param[] = {
+	FDI_LINK_TRAIN_400MV_0DB_SNB_A,
+	FDI_LINK_TRAIN_400MV_6DB_SNB_A,
+	FDI_LINK_TRAIN_600MV_3_5DB_SNB_A,
+	FDI_LINK_TRAIN_800MV_0DB_SNB_A,
+};
+
 static const int snb_b_fdi_train_param[] = {
 	FDI_LINK_TRAIN_400MV_0DB_SNB_B,
 	FDI_LINK_TRAIN_400MV_6DB_SNB_B,
@@ -2898,6 +2905,12 @@ static void gen6_fdi_link_train(struct drm_crtc *crtc)
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe;
 	u32 reg, temp, i, retry;
+	const int *train_param;
+
+	if (INTEL_STEPPING(dev) == 0)
+		train_param = snb_a_fdi_train_param;
+	else
+		train_param = snb_b_fdi_train_param;
 
 	/* Train 1: umask FDI RX Interrupt symbol_lock and bit_lock bit
 	   for train result */
@@ -2943,7 +2956,7 @@ static void gen6_fdi_link_train(struct drm_crtc *crtc)
 		reg = FDI_TX_CTL(pipe);
 		temp = I915_READ(reg);
 		temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
-		temp |= snb_b_fdi_train_param[i];
+		temp |= train_param[i];
 		I915_WRITE(reg, temp);
 
 		POSTING_READ(reg);
@@ -2996,7 +3009,7 @@ static void gen6_fdi_link_train(struct drm_crtc *crtc)
 		reg = FDI_TX_CTL(pipe);
 		temp = I915_READ(reg);
 		temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
-		temp |= snb_b_fdi_train_param[i];
+		temp |= train_param[i];
 		I915_WRITE(reg, temp);
 
 		POSTING_READ(reg);
-- 
1.8.4.2