drm/i915/display: Add compare config for MTL+ platforms

Currently, we may bump into pll mismatch errors during the
state verification stage. This happens when we try to use
fastset instead of full modeset. Hence, we would need to add
a check for pipe configuration to ensure that the sw and the
hw configuration will match. In case of hw and sw mismatch,
we would need to disable fastset and use full modeset instead.

v2: Fix C10 error on PLL comparison (BAT)
    Use memcmp instead of fixed loops for pll config
    comparison (Jani)
    Clean up and use intel_cx0pll_dump_hw_state() to dump
    pll information (Jani)
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240523134649.31452-3-mika.kahola@intel.com

drivers/gpu/drm/i915/display/intel_cx0_phy.c

@@ -2038,6 +2038,7 @@ static int intel_c10pll_calc_state(struct intel_crtc_state *crtc_state,
 		if (crtc_state->port_clock == tables[i]->clock) {
 			crtc_state->dpll_hw_state.cx0pll.c10 = *tables[i];
 			intel_c10pll_update_pll(crtc_state, encoder);
+			crtc_state->dpll_hw_state.cx0pll.use_c10 = true;
 
 			return 0;
 		}
@@ -2105,8 +2106,8 @@ static void intel_c10_pll_program(struct drm_i915_private *i915,
 		      MB_WRITE_COMMITTED);
 }
 
-void intel_c10pll_dump_hw_state(struct drm_i915_private *i915,
-				const struct intel_c10pll_state *hw_state)
+static void intel_c10pll_dump_hw_state(struct drm_i915_private *i915,
+				       const struct intel_c10pll_state *hw_state)
 {
 	bool fracen;
 	int i;
@@ -2277,6 +2278,7 @@ static int intel_c20pll_calc_state(struct intel_crtc_state *crtc_state,
 	for (i = 0; tables[i]; i++) {
 		if (crtc_state->port_clock == tables[i]->clock) {
 			crtc_state->dpll_hw_state.cx0pll.c20 = *tables[i];
+			crtc_state->dpll_hw_state.cx0pll.use_c10 = false;
 			return 0;
 		}
 	}
@@ -2410,8 +2412,8 @@ static void intel_c20pll_readout_hw_state(struct intel_encoder *encoder,
 	intel_cx0_phy_transaction_end(encoder, wakeref);
 }
 
-void intel_c20pll_dump_hw_state(struct drm_i915_private *i915,
-				const struct intel_c20pll_state *hw_state)
+static void intel_c20pll_dump_hw_state(struct drm_i915_private *i915,
+				       const struct intel_c20pll_state *hw_state)
 {
 	int i;
 
@@ -2430,6 +2432,15 @@ void intel_c20pll_dump_hw_state(struct drm_i915_private *i915,
 	}
 }
 
+void intel_cx0pll_dump_hw_state(struct drm_i915_private *i915,
+				const struct intel_cx0pll_state *hw_state)
+{
+	if (hw_state->use_c10)
+		intel_c10pll_dump_hw_state(i915, &hw_state->c10);
+	else
+		intel_c20pll_dump_hw_state(i915, &hw_state->c20);
+}
+
 static u8 intel_c20_get_dp_rate(u32 clock)
 {
 	switch (clock) {
@@ -3266,10 +3277,64 @@ static void intel_c10pll_state_verify(const struct intel_crtc_state *state,
 void intel_cx0pll_readout_hw_state(struct intel_encoder *encoder,
 				   struct intel_cx0pll_state *pll_state)
 {
-	if (intel_encoder_is_c10phy(encoder))
+	pll_state->use_c10 = false;
+
+	if (intel_encoder_is_c10phy(encoder)) {
 		intel_c10pll_readout_hw_state(encoder, &pll_state->c10);
-	else
+		pll_state->use_c10 = true;
+	} else {
 		intel_c20pll_readout_hw_state(encoder, &pll_state->c20);
+	}
+}
+
+static bool mtl_compare_hw_state_c10(const struct intel_c10pll_state *a,
+				     const struct intel_c10pll_state *b)
+{
+	if (a->tx != b->tx)
+		return false;
+
+	if (a->cmn != b->cmn)
+		return false;
+
+	if (memcmp(&a->pll, &b->pll, sizeof(a->pll)) != 0)
+		return false;
+
+	return true;
+}
+
+static bool mtl_compare_hw_state_c20(const struct intel_c20pll_state *a,
+				     const struct intel_c20pll_state *b)
+{
+	if (memcmp(&a->tx, &b->tx, sizeof(a->tx)) != 0)
+		return false;
+
+	if (memcmp(&a->cmn, &b->cmn, sizeof(a->cmn)) != 0)
+		return false;
+
+	if (a->tx[0] & C20_PHY_USE_MPLLB) {
+		if (memcmp(&a->mpllb, &b->mpllb, sizeof(a->mpllb)) != 0)
+			return false;
+	} else {
+		if (memcmp(&a->mplla, &b->mplla, sizeof(a->mplla)) != 0)
+			return false;
+	}
+
+	return true;
+}
+
+bool intel_cx0pll_compare_hw_state(const struct intel_cx0pll_state *a,
+				   const struct intel_cx0pll_state *b)
+{
+
+	if (a->use_c10 != b->use_c10)
+		return false;
+
+	if (a->use_c10)
+		return mtl_compare_hw_state_c10(&a->c10,
+						&b->c10);
+	else
+		return mtl_compare_hw_state_c20(&a->c20,
+						&b->c20);
 }
 
 int intel_cx0pll_calc_port_clock(struct intel_encoder *encoder,

drivers/gpu/drm/i915/display/intel_cx0_phy.h

@@ -35,12 +35,12 @@ void intel_cx0pll_readout_hw_state(struct intel_encoder *encoder,
 int intel_cx0pll_calc_port_clock(struct intel_encoder *encoder,
 				 const struct intel_cx0pll_state *pll_state);
 
-void intel_c10pll_dump_hw_state(struct drm_i915_private *dev_priv,
-				const struct intel_c10pll_state *hw_state);
+void intel_cx0pll_dump_hw_state(struct drm_i915_private *dev_priv,
+				const struct intel_cx0pll_state *hw_state);
 void intel_cx0pll_state_verify(struct intel_atomic_state *state,
 			       struct intel_crtc *crtc);
-void intel_c20pll_dump_hw_state(struct drm_i915_private *i915,
-				const struct intel_c20pll_state *hw_state);
+bool intel_cx0pll_compare_hw_state(const struct intel_cx0pll_state *a,
+				   const struct intel_cx0pll_state *b);
 void intel_cx0_phy_set_signal_levels(struct intel_encoder *encoder,
 				     const struct intel_crtc_state *crtc_state);
 int intel_cx0_phy_check_hdmi_link_rate(struct intel_hdmi *hdmi, int clock);

drivers/gpu/drm/i915/display/intel_display.c

@@ -67,6 +67,7 @@
 #include "intel_crtc.h"
 #include "intel_crtc_state_dump.h"
 #include "intel_cursor_regs.h"
+#include "intel_cx0_phy.h"
 #include "intel_ddi.h"
 #include "intel_de.h"
 #include "intel_display_driver.h"
@@ -4983,6 +4984,24 @@ pipe_config_pll_mismatch(struct drm_printer *p, bool fastset,
 	intel_dpll_dump_hw_state(i915, p, b);
 }
 
+static void
+pipe_config_cx0pll_mismatch(struct drm_printer *p, bool fastset,
+			    const struct intel_crtc *crtc,
+			    const char *name,
+			    const struct intel_cx0pll_state *a,
+			    const struct intel_cx0pll_state *b)
+{
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	char *chipname = a->use_c10 ? "C10" : "C20";
+
+	pipe_config_mismatch(p, fastset, crtc, name, chipname);
+
+	drm_printf(p, "expected:\n");
+	intel_cx0pll_dump_hw_state(i915, a);
+	drm_printf(p, "found:\n");
+	intel_cx0pll_dump_hw_state(i915, b);
+}
+
 bool
 intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 			  const struct intel_crtc_state *pipe_config,
@@ -5086,6 +5105,16 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 	} \
 } while (0)
 
+#define PIPE_CONF_CHECK_PLL_CX0(name) do { \
+	if (!intel_cx0pll_compare_hw_state(&current_config->name, \
+					   &pipe_config->name)) { \
+		pipe_config_cx0pll_mismatch(&p, fastset, crtc, __stringify(name), \
+					    &current_config->name, \
+					    &pipe_config->name); \
+		ret = false; \
+	} \
+} while (0)
+
 #define PIPE_CONF_CHECK_TIMINGS(name) do {     \
 	PIPE_CONF_CHECK_I(name.crtc_hdisplay); \
 	PIPE_CONF_CHECK_I(name.crtc_htotal); \
@@ -5318,6 +5347,10 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 	if (dev_priv->display.dpll.mgr || HAS_GMCH(dev_priv))
 		PIPE_CONF_CHECK_PLL(dpll_hw_state);
 
+	/* FIXME convert MTL+ platforms over to dpll_mgr */
+	if (DISPLAY_VER(dev_priv) >= 14)
+		PIPE_CONF_CHECK_PLL_CX0(dpll_hw_state.cx0pll);
+
 	PIPE_CONF_CHECK_X(dsi_pll.ctrl);
 	PIPE_CONF_CHECK_X(dsi_pll.div);
 

drivers/gpu/drm/i915/display/intel_dpll_mgr.h

@@ -264,6 +264,7 @@ struct intel_cx0pll_state {
 		struct intel_c20pll_state c20;
 	};
 	bool ssc_enabled;
+	bool use_c10;
 };
 
 struct intel_dpll_hw_state {