drm/i915: Track minimum acceptable cdclk instead of "minimum dotclock"

Make the min_pixclk thing less confusing by changing it to track
the minimum acceptable cdclk frequency instead. This means moving
the application of the guardbands to a slightly higher level from
the low level platform specific calc_cdclk() functions.

The immediate benefit is elimination of the confusing 2x factors
on GLK/CNL+ in the audio workarounds (which stems from the fact
that the pipes produce two pixels per clock).

v2: Keep cdclk higher on CNL to workaround missing DDI clock voltage handling
v3: Squash with the CNL cdclk limits patch (DK)
v4: s/intel_min_cdclk/intel_pixel_rate_to_cdclk/ (DK)

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170830185703.8189-1-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -569,6 +569,15 @@ struct i915_hotplug {
 	     (__i)++) \
 		for_each_if (plane_state)
 
+#define for_each_new_intel_crtc_in_state(__state, crtc, new_crtc_state, __i) \
+	for ((__i) = 0; \
+	     (__i) < (__state)->base.dev->mode_config.num_crtc && \
+		     ((crtc) = to_intel_crtc((__state)->base.crtcs[__i].ptr), \
+		      (new_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].new_state), 1); \
+	     (__i)++) \
+		for_each_if (crtc)
+
+
 struct drm_i915_private;
 struct i915_mm_struct;
 struct i915_mmu_object;
@@ -2335,7 +2344,8 @@ struct drm_i915_private {
 	struct mutex dpll_lock;
 
 	unsigned int active_crtcs;
-	unsigned int min_pixclk[I915_MAX_PIPES];
+	/* minimum acceptable cdclk for each pipe */
+	int min_cdclk[I915_MAX_PIPES];
 
 	int dpio_phy_iosf_port[I915_NUM_PHYS_VLV];
 

drivers/gpu/drm/i915/intel_display.c

@@ -6038,7 +6038,7 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc,
 	intel_crtc->enabled_power_domains = 0;
 
 	dev_priv->active_crtcs &= ~(1 << intel_crtc->pipe);
-	dev_priv->min_pixclk[intel_crtc->pipe] = 0;
+	dev_priv->min_cdclk[intel_crtc->pipe] = 0;
 }
 
 /*
@@ -12631,8 +12631,8 @@ static int intel_atomic_commit(struct drm_device *dev,
 	intel_atomic_track_fbs(state);
 
 	if (intel_state->modeset) {
-		memcpy(dev_priv->min_pixclk, intel_state->min_pixclk,
-		       sizeof(intel_state->min_pixclk));
+		memcpy(dev_priv->min_cdclk, intel_state->min_cdclk,
+		       sizeof(intel_state->min_cdclk));
 		dev_priv->active_crtcs = intel_state->active_crtcs;
 		dev_priv->cdclk.logical = intel_state->cdclk.logical;
 		dev_priv->cdclk.actual = intel_state->cdclk.actual;
@@ -15097,7 +15097,7 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 	for_each_intel_crtc(dev, crtc) {
 		struct intel_crtc_state *crtc_state =
 			to_intel_crtc_state(crtc->base.state);
-		int pixclk = 0;
+		int min_cdclk = 0;
 
 		memset(&crtc->base.mode, 0, sizeof(crtc->base.mode));
 		if (crtc_state->base.active) {
@@ -15118,22 +15118,15 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 
 			intel_crtc_compute_pixel_rate(crtc_state);
 
-			if (INTEL_GEN(dev_priv) >= 9 || IS_BROADWELL(dev_priv) ||
-			    IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
-				pixclk = crtc_state->pixel_rate;
-			else
-				WARN_ON(dev_priv->display.modeset_calc_cdclk);
-
-			/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
-			if (IS_BROADWELL(dev_priv) && crtc_state->ips_enabled)
-				pixclk = DIV_ROUND_UP(pixclk * 100, 95);
+			if (dev_priv->display.modeset_calc_cdclk)
+				min_cdclk = intel_crtc_compute_min_cdclk(crtc_state);
 
 			drm_calc_timestamping_constants(&crtc->base,
 							&crtc_state->base.adjusted_mode);
 			update_scanline_offset(crtc);
 		}
 
-		dev_priv->min_pixclk[crtc->pipe] = pixclk;
+		dev_priv->min_cdclk[crtc->pipe] = min_cdclk;
 
 		intel_pipe_config_sanity_check(dev_priv, crtc_state);
 	}

drivers/gpu/drm/i915/intel_drv.h

@@ -384,7 +384,8 @@ struct intel_atomic_state {
 	unsigned int active_pipe_changes;
 
 	unsigned int active_crtcs;
-	unsigned int min_pixclk[I915_MAX_PIPES];
+	/* minimum acceptable cdclk for each pipe */
+	int min_cdclk[I915_MAX_PIPES];
 
 	struct intel_shared_dpll_state shared_dpll[I915_NUM_PLLS];
 
@@ -1290,6 +1291,7 @@ void intel_audio_init(struct drm_i915_private *dev_priv);
 void intel_audio_deinit(struct drm_i915_private *dev_priv);
 
 /* intel_cdclk.c */
+int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state);
 void skl_init_cdclk(struct drm_i915_private *dev_priv);
 void skl_uninit_cdclk(struct drm_i915_private *dev_priv);
 void cnl_init_cdclk(struct drm_i915_private *dev_priv);