drm/i915: Allow fuzzy matching in pipe_config_compare, v2.

Instead of doing ad-hoc checks we already have a way of checking
if the state is compatible or not. Use this to force a modeset.

Only during modesets, or with PIPE_CONFIG_QUIRK_INHERITED_MODE
we should check if a full modeset is really needed.

Fastboot will allow the adjust parameter to ignore some stuff
too, and it will fix up differences in state that are ignored
by the compare function.

Changes since v1:
- Increase the value of the lowest m/n to prevent truncation.
- Dump pipe config when fastboot's used, without a modeset.
- Add adjust parameter to intel_compare_link_m_n, which is
  used to adjust m2_n2 if it's a multiple of m_n.
- Add exact parameter intel_compare_m_n.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -12288,19 +12288,6 @@ intel_modeset_pipe_config(struct drm_crtc *crtc,
 	DRM_DEBUG_KMS("plane bpp: %i, pipe bpp: %i, dithering: %i\n",
 		      base_bpp, pipe_config->pipe_bpp, pipe_config->dither);
 
-	/* Check if we need to force a modeset */
-	if (pipe_config->has_audio !=
-	    to_intel_crtc_state(crtc->state)->has_audio) {
-		pipe_config->base.mode_changed = true;
-		ret = drm_atomic_add_affected_planes(state, crtc);
-	}
-
-	/*
-	 * Note we have an issue here with infoframes: current code
-	 * only updates them on the full mode set path per hw
-	 * requirements.  So here we should be checking for any
-	 * required changes and forcing a mode set.
-	 */
 fail:
 	return ret;
 }
@@ -12404,27 +12391,133 @@ static bool intel_fuzzy_clock_check(int clock1, int clock2)
 			    base.head) \
 		if (mask & (1 <<(intel_crtc)->pipe))
 
+
+static bool
+intel_compare_m_n(unsigned int m, unsigned int n,
+		  unsigned int m2, unsigned int n2,
+		  bool exact)
+{
+	if (m == m2 && n == n2)
+		return true;
+
+	if (exact || !m || !n || !m2 || !n2)
+		return false;
+
+	BUILD_BUG_ON(DATA_LINK_M_N_MASK > INT_MAX);
+
+	if (m > m2) {
+		while (m > m2) {
+			m2 <<= 1;
+			n2 <<= 1;
+		}
+	} else if (m < m2) {
+		while (m < m2) {
+			m <<= 1;
+			n <<= 1;
+		}
+	}
+
+	return m == m2 && n == n2;
+}
+
+static bool
+intel_compare_link_m_n(const struct intel_link_m_n *m_n,
+		       struct intel_link_m_n *m2_n2,
+		       bool adjust)
+{
+	if (m_n->tu == m2_n2->tu &&
+	    intel_compare_m_n(m_n->gmch_m, m_n->gmch_n,
+			      m2_n2->gmch_m, m2_n2->gmch_n, !adjust) &&
+	    intel_compare_m_n(m_n->link_m, m_n->link_n,
+			      m2_n2->link_m, m2_n2->link_n, !adjust)) {
+		if (adjust)
+			*m2_n2 = *m_n;
+
+		return true;
+	}
+
+	return false;
+}
+
 static bool
 intel_pipe_config_compare(struct drm_device *dev,
 			  struct intel_crtc_state *current_config,
-			  struct intel_crtc_state *pipe_config)
+			  struct intel_crtc_state *pipe_config,
+			  bool adjust)
 {
+	bool ret = true;
+
+#define INTEL_ERR_OR_DBG_KMS(fmt, ...) \
+	do { \
+		if (!adjust) \
+			DRM_ERROR(fmt, ##__VA_ARGS__); \
+		else \
+			DRM_DEBUG_KMS(fmt, ##__VA_ARGS__); \
+	} while (0)
+
 #define PIPE_CONF_CHECK_X(name)	\
 	if (current_config->name != pipe_config->name) { \
-		DRM_ERROR("mismatch in " #name " " \
+		INTEL_ERR_OR_DBG_KMS("mismatch in " #name " " \
 			  "(expected 0x%08x, found 0x%08x)\n", \
 			  current_config->name, \
 			  pipe_config->name); \
-		return false; \
+		ret = false; \
 	}
 
 #define PIPE_CONF_CHECK_I(name)	\
 	if (current_config->name != pipe_config->name) { \
-		DRM_ERROR("mismatch in " #name " " \
+		INTEL_ERR_OR_DBG_KMS("mismatch in " #name " " \
 			  "(expected %i, found %i)\n", \
 			  current_config->name, \
 			  pipe_config->name); \
-		return false; \
+		ret = false; \
+	}
+
+#define PIPE_CONF_CHECK_M_N(name) \
+	if (!intel_compare_link_m_n(&current_config->name, \
+				    &pipe_config->name,\
+				    adjust)) { \
+		INTEL_ERR_OR_DBG_KMS("mismatch in " #name " " \
+			  "(expected tu %i gmch %i/%i link %i/%i, " \
+			  "found tu %i, gmch %i/%i link %i/%i)\n", \
+			  current_config->name.tu, \
+			  current_config->name.gmch_m, \
+			  current_config->name.gmch_n, \
+			  current_config->name.link_m, \
+			  current_config->name.link_n, \
+			  pipe_config->name.tu, \
+			  pipe_config->name.gmch_m, \
+			  pipe_config->name.gmch_n, \
+			  pipe_config->name.link_m, \
+			  pipe_config->name.link_n); \
+		ret = false; \
+	}
+
+#define PIPE_CONF_CHECK_M_N_ALT(name, alt_name) \
+	if (!intel_compare_link_m_n(&current_config->name, \
+				    &pipe_config->name, adjust) && \
+	    !intel_compare_link_m_n(&current_config->alt_name, \
+				    &pipe_config->name, adjust)) { \
+		INTEL_ERR_OR_DBG_KMS("mismatch in " #name " " \
+			  "(expected tu %i gmch %i/%i link %i/%i, " \
+			  "or tu %i gmch %i/%i link %i/%i, " \
+			  "found tu %i, gmch %i/%i link %i/%i)\n", \
+			  current_config->name.tu, \
+			  current_config->name.gmch_m, \
+			  current_config->name.gmch_n, \
+			  current_config->name.link_m, \
+			  current_config->name.link_n, \
+			  current_config->alt_name.tu, \
+			  current_config->alt_name.gmch_m, \
+			  current_config->alt_name.gmch_n, \
+			  current_config->alt_name.link_m, \
+			  current_config->alt_name.link_n, \
+			  pipe_config->name.tu, \
+			  pipe_config->name.gmch_m, \
+			  pipe_config->name.gmch_n, \
+			  pipe_config->name.link_m, \
+			  pipe_config->name.link_n); \
+		ret = false; \
 	}
 
 /* This is required for BDW+ where there is only one set of registers for
@@ -12435,30 +12528,30 @@ intel_pipe_config_compare(struct drm_device *dev,
 #define PIPE_CONF_CHECK_I_ALT(name, alt_name) \
 	if ((current_config->name != pipe_config->name) && \
 		(current_config->alt_name != pipe_config->name)) { \
-			DRM_ERROR("mismatch in " #name " " \
+			INTEL_ERR_OR_DBG_KMS("mismatch in " #name " " \
 				  "(expected %i or %i, found %i)\n", \
 				  current_config->name, \
 				  current_config->alt_name, \
 				  pipe_config->name); \
-			return false; \
+			ret = false; \
 	}
 
 #define PIPE_CONF_CHECK_FLAGS(name, mask)	\
 	if ((current_config->name ^ pipe_config->name) & (mask)) { \
-		DRM_ERROR("mismatch in " #name "(" #mask ") "	   \
+		INTEL_ERR_OR_DBG_KMS("mismatch in " #name "(" #mask ") " \
 			  "(expected %i, found %i)\n", \
 			  current_config->name & (mask), \
 			  pipe_config->name & (mask)); \
-		return false; \
+		ret = false; \
 	}
 
 #define PIPE_CONF_CHECK_CLOCK_FUZZY(name) \
 	if (!intel_fuzzy_clock_check(current_config->name, pipe_config->name)) { \
-		DRM_ERROR("mismatch in " #name " " \
+		INTEL_ERR_OR_DBG_KMS("mismatch in " #name " " \
 			  "(expected %i, found %i)\n", \
 			  current_config->name, \
 			  pipe_config->name); \
-		return false; \
+		ret = false; \
 	}
 
 #define PIPE_CONF_QUIRK(quirk)	\
@@ -12468,35 +12561,18 @@ intel_pipe_config_compare(struct drm_device *dev,
 
 	PIPE_CONF_CHECK_I(has_pch_encoder);
 	PIPE_CONF_CHECK_I(fdi_lanes);
-	PIPE_CONF_CHECK_I(fdi_m_n.gmch_m);
-	PIPE_CONF_CHECK_I(fdi_m_n.gmch_n);
-	PIPE_CONF_CHECK_I(fdi_m_n.link_m);
-	PIPE_CONF_CHECK_I(fdi_m_n.link_n);
-	PIPE_CONF_CHECK_I(fdi_m_n.tu);
+	PIPE_CONF_CHECK_M_N(fdi_m_n);
 
 	PIPE_CONF_CHECK_I(has_dp_encoder);
 
 	if (INTEL_INFO(dev)->gen < 8) {
-		PIPE_CONF_CHECK_I(dp_m_n.gmch_m);
-		PIPE_CONF_CHECK_I(dp_m_n.gmch_n);
-		PIPE_CONF_CHECK_I(dp_m_n.link_m);
-		PIPE_CONF_CHECK_I(dp_m_n.link_n);
-		PIPE_CONF_CHECK_I(dp_m_n.tu);
-
-		if (current_config->has_drrs) {
-			PIPE_CONF_CHECK_I(dp_m2_n2.gmch_m);
-			PIPE_CONF_CHECK_I(dp_m2_n2.gmch_n);
-			PIPE_CONF_CHECK_I(dp_m2_n2.link_m);
-			PIPE_CONF_CHECK_I(dp_m2_n2.link_n);
-			PIPE_CONF_CHECK_I(dp_m2_n2.tu);
-		}
-	} else {
-		PIPE_CONF_CHECK_I_ALT(dp_m_n.gmch_m, dp_m2_n2.gmch_m);
-		PIPE_CONF_CHECK_I_ALT(dp_m_n.gmch_n, dp_m2_n2.gmch_n);
-		PIPE_CONF_CHECK_I_ALT(dp_m_n.link_m, dp_m2_n2.link_m);
-		PIPE_CONF_CHECK_I_ALT(dp_m_n.link_n, dp_m2_n2.link_n);
-		PIPE_CONF_CHECK_I_ALT(dp_m_n.tu, dp_m2_n2.tu);
-	}
+		PIPE_CONF_CHECK_M_N(dp_m_n);
+
+		PIPE_CONF_CHECK_I(has_drrs);
+		if (current_config->has_drrs)
+			PIPE_CONF_CHECK_M_N(dp_m2_n2);
+	} else
+		PIPE_CONF_CHECK_M_N_ALT(dp_m_n, dp_m2_n2);
 
 	PIPE_CONF_CHECK_I(base.adjusted_mode.crtc_hdisplay);
 	PIPE_CONF_CHECK_I(base.adjusted_mode.crtc_htotal);
@@ -12592,8 +12668,9 @@ intel_pipe_config_compare(struct drm_device *dev,
 #undef PIPE_CONF_CHECK_FLAGS
 #undef PIPE_CONF_CHECK_CLOCK_FUZZY
 #undef PIPE_CONF_QUIRK
+#undef INTEL_ERR_OR_DBG_KMS
 
-	return true;
+	return ret;
 }
 
 static void check_wm_state(struct drm_device *dev)
@@ -12785,8 +12862,11 @@ check_crtc_state(struct drm_device *dev)
 		     "transitional active state does not match atomic hw state "
 		     "(expected %i, found %i)\n", crtc->base.state->active, crtc->active);
 
-		if (active &&
-		    !intel_pipe_config_compare(dev, crtc->config, &pipe_config)) {
+		if (!active)
+			continue;
+
+		if (!intel_pipe_config_compare(dev, crtc->config,
+					       &pipe_config, false)) {
 			I915_STATE_WARN(1, "pipe state doesn't match!\n");
 			intel_dump_pipe_config(crtc, &pipe_config,
 					       "[hw state]");
@@ -13087,14 +13167,17 @@ intel_modeset_compute_config(struct drm_atomic_state *state)
 		return ret;
 
 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		struct intel_crtc_state *pipe_config =
+			to_intel_crtc_state(crtc_state);
+		bool modeset, recalc;
+
 		if (!crtc_state->enable) {
 			if (needs_modeset(crtc_state))
 				any_ms = true;
 			continue;
 		}
 
-		if (to_intel_crtc_state(crtc_state)->quirks &
-		    PIPE_CONFIG_QUIRK_INITIAL_PLANES) {
+		if (pipe_config->quirks & PIPE_CONFIG_QUIRK_INITIAL_PLANES) {
 			ret = drm_atomic_add_affected_planes(state, crtc);
 			if (ret)
 				return ret;
@@ -13107,23 +13190,36 @@ intel_modeset_compute_config(struct drm_atomic_state *state)
 			 */
 		}
 
-		if (!needs_modeset(crtc_state)) {
+		modeset = needs_modeset(crtc_state);
+		recalc = pipe_config->quirks & PIPE_CONFIG_QUIRK_INHERITED_MODE;
+
+		if (!modeset && !recalc)
+			continue;
+
+		if (recalc) {
 			ret = drm_atomic_add_affected_connectors(state, crtc);
 			if (ret)
 				return ret;
 		}
 
-		ret = intel_modeset_pipe_config(crtc,
-					to_intel_crtc_state(crtc_state));
+		ret = intel_modeset_pipe_config(crtc, pipe_config);
 		if (ret)
 			return ret;
 
-		if (needs_modeset(crtc_state))
-			any_ms = true;
+		if (recalc && !intel_pipe_config_compare(state->dev,
+					to_intel_crtc_state(crtc->state),
+					pipe_config, true)) {
+			modeset = crtc_state->mode_changed = true;
+
+			ret = drm_atomic_add_affected_planes(state, crtc);
+			if (ret)
+				return ret;
+		}
 
+		any_ms = modeset;
 		intel_dump_pipe_config(to_intel_crtc(crtc),
-				       to_intel_crtc_state(crtc_state),
-				       "[modeset]");
+				       pipe_config,
+				       modeset ? "[modeset]" : "[fastboot]");
 	}
 
 	if (any_ms) {