drm/i915: Skip some timing checks on BXT/GLK DSI transcoders

Apparently some BXT/GLK systems have DSI panels whose timings
don't agree with the normal cpu transcoder hblank>=32 limitation.
This is perhaps fine as there are no specific hblank/etc. limits
listed for the BXT/GLK DSI transcoders.

Move those checks out from the global intel_mode_valid() into
into connector specific .mode_valid() hooks, skipping BXT/GLK
DSI connectors. We'll leave the basic [hv]display/[hv]total
checks in intel_mode_valid() as those seem like sensible upper
limits regardless of the transcoder used.

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9720
Fixes: 8f4b1068 ("drm/i915: Check some transcoder timing minimum limits")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127145028.4899-1-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -1440,6 +1440,13 @@ static void gen11_dsi_post_disable(struct intel_atomic_state *state,
 static enum drm_mode_status gen11_dsi_mode_valid(struct drm_connector *connector,
 						 struct drm_display_mode *mode)
 {
+	struct drm_i915_private *i915 = to_i915(connector->dev);
+	enum drm_mode_status status;
+
+	status = intel_cpu_transcoder_mode_valid(i915, mode);
+	if (status != MODE_OK)
+		return status;
+
 	/* FIXME: DSC? */
 	return intel_dsi_mode_valid(connector, mode);
 }

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

@@ -348,8 +348,13 @@ intel_crt_mode_valid(struct drm_connector *connector,
 	struct drm_device *dev = connector->dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	int max_dotclk = dev_priv->max_dotclk_freq;
+	enum drm_mode_status status;
 	int max_clock;
 
+	status = intel_cpu_transcoder_mode_valid(dev_priv, mode);
+	if (status != MODE_OK)
+		return status;
+
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;
 

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

@@ -7734,6 +7734,16 @@ enum drm_mode_status intel_mode_valid(struct drm_device *dev,
 	    mode->vtotal > vtotal_max)
 		return MODE_V_ILLEGAL;
 
+	return MODE_OK;
+}
+
+enum drm_mode_status intel_cpu_transcoder_mode_valid(struct drm_i915_private *dev_priv,
+						     const struct drm_display_mode *mode)
+{
+	/*
+	 * Additional transcoder timing limits,
+	 * excluding BXT/GLK DSI transcoders.
+	 */
 	if (DISPLAY_VER(dev_priv) >= 5) {
 		if (mode->hdisplay < 64 ||
 		    mode->htotal - mode->hdisplay < 32)

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

@@ -402,6 +402,9 @@ enum drm_mode_status
 intel_mode_valid_max_plane_size(struct drm_i915_private *dev_priv,
 				const struct drm_display_mode *mode,
 				bool bigjoiner);
+enum drm_mode_status
+intel_cpu_transcoder_mode_valid(struct drm_i915_private *i915,
+				const struct drm_display_mode *mode);
 enum phy intel_port_to_phy(struct drm_i915_private *i915, enum port port);
 bool is_trans_port_sync_mode(const struct intel_crtc_state *state);
 bool is_trans_port_sync_master(const struct intel_crtc_state *state);

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

@@ -1227,6 +1227,10 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 	enum drm_mode_status status;
 	bool dsc = false, bigjoiner = false;
 
+	status = intel_cpu_transcoder_mode_valid(dev_priv, mode);
+	if (status != MODE_OK)
+		return status;
+
 	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		return MODE_H_ILLEGAL;
 

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

@@ -1282,6 +1282,10 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
 		return 0;
 	}
 
+	*status = intel_cpu_transcoder_mode_valid(dev_priv, mode);
+	if (*status != MODE_OK)
+		return 0;
+
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN) {
 		*status = MODE_NO_DBLESCAN;
 		return 0;

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

@@ -217,11 +217,17 @@ intel_dvo_mode_valid(struct drm_connector *_connector,
 		     struct drm_display_mode *mode)
 {
 	struct intel_connector *connector = to_intel_connector(_connector);
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
 	struct intel_dvo *intel_dvo = intel_attached_dvo(connector);
 	const struct drm_display_mode *fixed_mode =
 		intel_panel_fixed_mode(connector, mode);
 	int max_dotclk = to_i915(connector->base.dev)->max_dotclk_freq;
 	int target_clock = mode->clock;
+	enum drm_mode_status status;
+
+	status = intel_cpu_transcoder_mode_valid(i915, mode);
+	if (status != MODE_OK)
+		return status;
 
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;

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

@@ -1983,6 +1983,10 @@ intel_hdmi_mode_valid(struct drm_connector *connector,
 	bool ycbcr_420_only;
 	enum intel_output_format sink_format;
 
+	status = intel_cpu_transcoder_mode_valid(dev_priv, mode);
+	if (status != MODE_OK)
+		return status;
+
 	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) == DRM_MODE_FLAG_3D_FRAME_PACKING)
 		clock *= 2;
 

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

@@ -389,11 +389,16 @@ intel_lvds_mode_valid(struct drm_connector *_connector,
 		      struct drm_display_mode *mode)
 {
 	struct intel_connector *connector = to_intel_connector(_connector);
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
 	const struct drm_display_mode *fixed_mode =
 		intel_panel_fixed_mode(connector, mode);
 	int max_pixclk = to_i915(connector->base.dev)->max_dotclk_freq;
 	enum drm_mode_status status;
 
+	status = intel_cpu_transcoder_mode_valid(i915, mode);
+	if (status != MODE_OK)
+		return status;
+
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;
 

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

@@ -1930,13 +1930,19 @@ static enum drm_mode_status
 intel_sdvo_mode_valid(struct drm_connector *connector,
 		      struct drm_display_mode *mode)
 {
+	struct drm_i915_private *i915 = to_i915(connector->dev);
 	struct intel_sdvo *intel_sdvo = intel_attached_sdvo(to_intel_connector(connector));
 	struct intel_sdvo_connector *intel_sdvo_connector =
 		to_intel_sdvo_connector(connector);
-	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
 	bool has_hdmi_sink = intel_has_hdmi_sink(intel_sdvo_connector, connector->state);
+	int max_dotclk = i915->max_dotclk_freq;
+	enum drm_mode_status status;
 	int clock = mode->clock;
 
+	status = intel_cpu_transcoder_mode_valid(i915, mode);
+	if (status != MODE_OK)
+		return status;
+
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;
 

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

@@ -958,8 +958,14 @@ static enum drm_mode_status
 intel_tv_mode_valid(struct drm_connector *connector,
 		    struct drm_display_mode *mode)
 {
+	struct drm_i915_private *i915 = to_i915(connector->dev);
 	const struct tv_mode *tv_mode = intel_tv_mode_find(connector->state);
-	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
+	int max_dotclk = i915->max_dotclk_freq;
+	enum drm_mode_status status;
+
+	status = intel_cpu_transcoder_mode_valid(i915, mode);
+	if (status != MODE_OK)
+		return status;
 
 	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return MODE_NO_DBLESCAN;

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

@@ -1544,9 +1544,25 @@ static const struct drm_encoder_funcs intel_dsi_funcs = {
 	.destroy = intel_dsi_encoder_destroy,
 };
 
+static enum drm_mode_status vlv_dsi_mode_valid(struct drm_connector *connector,
+					       struct drm_display_mode *mode)
+{
+	struct drm_i915_private *i915 = to_i915(connector->dev);
+
+	if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) {
+		enum drm_mode_status status;
+
+		status = intel_cpu_transcoder_mode_valid(i915, mode);
+		if (status != MODE_OK)
+			return status;
+	}
+
+	return intel_dsi_mode_valid(connector, mode);
+}
+
 static const struct drm_connector_helper_funcs intel_dsi_connector_helper_funcs = {
 	.get_modes = intel_dsi_get_modes,
-	.mode_valid = intel_dsi_mode_valid,
+	.mode_valid = vlv_dsi_mode_valid,
 	.atomic_check = intel_digital_connector_atomic_check,
 };