[Intel-gfx] [PATCH 15/18] drm/i915: set the correct eDP aux channel clock divider on DDI

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

The cdclk frequency is not always the same, so the value here should
be adjusted to match it.

Version 2: call intel_ddi_get_cdclk_freq instead of reading
CDCLK_FREQ, because the register is just for earlier HW steppings.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 2 +-
 drivers/gpu/drm/i915/intel_dp.c  | 4 +++-
 drivers/gpu/drm/i915/intel_drv.h | 1 +
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 106c375..30b0db7 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1239,7 +1239,7 @@ void intel_disable_ddi(struct intel_encoder *encoder)
 	/* This will be needed in the future, so leave it here for now */
 }
 
-static int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv)
+int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv)
 {
 	if (I915_READ(HSW_FUSE_STRAP) & HSW_CDCLK_LIMIT)
 		return 450;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f15ea22..6d30b2d 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -370,7 +370,9 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
 	 * clock divider.
 	 */
 	if (is_cpu_edp(intel_dp)) {
-		if (IS_VALLEYVIEW(dev))
+		if (IS_HASWELL(dev))
+			aux_clock_divider = intel_ddi_get_cdclk_freq(dev_priv) >> 1;
+		else if (IS_VALLEYVIEW(dev))
 			aux_clock_divider = 100;
 		else if (IS_GEN6(dev) || IS_GEN7(dev))
 			aux_clock_divider = 200; /* SNB & IVB eDP input clock at 400Mhz */
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 65927d9..c05e892 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -609,6 +609,7 @@ extern bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
 extern void intel_ddi_mode_set(struct drm_encoder *encoder,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode);
+extern int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv);
 extern void intel_ddi_pll_init(struct drm_device *dev);
 extern void intel_ddi_enable_pipe_func(struct drm_crtc *crtc);
 extern void intel_ddi_disable_transcoder_func(struct drm_i915_private *dev_priv,
-- 
1.7.11.4