[PATCH 08/14] drm/i915: fix Haswell DP M/N registers

[Paulo Zanoni <przanoni@gmail.com>]

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

We have to write the correct values inside intel_dp_set_m_n and then
prevent these values from being overwritten later.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 3 ++-
 drivers/gpu/drm/i915/intel_dp.c      | 7 ++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f48986b9..ba40aa7 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5356,7 +5356,8 @@ static int haswell_crtc_mode_set(struct drm_crtc *crtc,
 
 	intel_set_pipe_timings(intel_crtc, mode, adjusted_mode);
 
-	ironlake_set_m_n(crtc, mode, adjusted_mode);
+	if (!(is_dp && !is_cpu_edp))
+		ironlake_set_m_n(crtc, mode, adjusted_mode);
 
 	if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
 		if (is_cpu_edp)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 52b5453..22702df 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -793,7 +793,12 @@ intel_dp_set_m_n(struct drm_crtc *crtc, struct drm_display_mode *mode,
 	intel_dp_compute_m_n(intel_crtc->bpp, lane_count,
 			     mode->clock, adjusted_mode->clock, &m_n);
 
-	if (HAS_PCH_SPLIT(dev)) {
+	if (IS_HASWELL(dev)) {
+		I915_WRITE(PIPE_DATA_M1(pipe), TU_SIZE(m_n.tu) | m_n.gmch_m);
+		I915_WRITE(PIPE_DATA_N1(pipe), m_n.gmch_n);
+		I915_WRITE(PIPE_LINK_M1(pipe), m_n.link_m);
+		I915_WRITE(PIPE_LINK_N1(pipe), m_n.link_n);
+	} else if (HAS_PCH_SPLIT(dev)) {
 		I915_WRITE(TRANSDATA_M1(pipe), TU_SIZE(m_n.tu) | m_n.gmch_m);
 		I915_WRITE(TRANSDATA_N1(pipe), m_n.gmch_n);
 		I915_WRITE(TRANSDPLINK_M1(pipe), m_n.link_m);
-- 
1.7.11.4