drm/i915: Set M2_N2 registers during mode set

For Gen < 8, set M2_N2 registers on every mode set. This is required to make
sure M2_N2 registers are set during boot, resume from sleep for cross-
checking the state. The register is set only if DRRS is supported.

v2: Patch rebased

v3: Daniel's review comments
	- Removed HAS_DRRS(dev) and added bool has_drrs to pipe_config to
	track drrs support

v4: Jesse's review comments
	- Made changes to set m2_n2 in intel_dp_set_m_n()

Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 4b2664bd5b81..7a3cac095afe 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -324,6 +324,7 @@ struct intel_crtc_config {
 
         /* m2_n2 for eDP downclock */
         struct intel_link_m_n dp_m2_n2;
+        bool has_drrs;
 
         /*
          * Frequence the dpll for the port should run at. Differs from the
@@ -877,6 +878,7 @@ void hsw_enable_pc8(struct drm_i915_private *dev_priv);
 void hsw_disable_pc8(struct drm_i915_private *dev_priv);
 void intel_dp_get_m_n(struct intel_crtc *crtc,
                       struct intel_crtc_config *pipe_config);
+void intel_dp_set_m_n(struct intel_crtc *crtc);
 int intel_dotclock_calculate(int link_freq, const struct intel_link_m_n *m_n);
 void
 ironlake_check_encoder_dotclock(const struct intel_crtc_config *pipe_config,
@@ -892,7 +894,6 @@ void intel_mode_from_pipe_config(struct drm_display_mode *mode,
 int intel_format_to_fourcc(int format);
 void intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc);
 
-
 /* intel_dp.c */
 void intel_dp_init(struct drm_device *dev, int output_reg, enum port port);
 bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port,