drm/i915: Get panel_type from OpRegion panel details

vsyrjala · vsyrjala · commit a05628195a0d · 2016-04-12T13:23:43.000+03:00
We've had problems on several occasions with using the panel type from the VBT block 40. Usually it seems to be 2, which often doesn't give us the correct timings for the panel. After some more digging I found a way to get a panel type via the OpRegion SWSCI GBDA "Get Panel Details" method. Let's try to use it. The spec has this to say about the output: "Bits [15:8] - Panel Type Bits contain the panel type user setting from CMOS 00h = Not Valid, use default Panel Type & Timings from VBT 01h - 0Fh = Panel Number" Another version of the spec lists the valid range as 1-16, which makes more sense since VBT supports 16 panels. Based on actual results from Rob's G45, 1-16 is what we need to accept. The other bits in the output don't look relevant for the problem at hand. The input is specified as: "Bits [31:4] - Reserved Reserved (must be zero) Bits [3:0] - Panel Number These bits contain the sequential index of Panel, starting at 0 and counting upwards from the first integrated Internal Flat-Panel Display Encoder present, and then from the first external Display Encoder (e.g., S/DVO-B then S/DVO-C) which supports Internal Flat-Panels. 0h - 0Fh = Panel number" For now I've just hardcoded the input panel number as 0. That would seem like a decent choise for LVDS. Not so sure about eDP when port != A. v2: Accept values 1-16 Filter out bogus results in opregion code (Jani) Add debug logging for all the different branches (Jani) Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Rob Kramer <rob@solution-space.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94825 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1460359431-11003-1-git-send-email-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula <jani.nikula@intel.com> Tested-by: Rob Kramer <rob@solution-space.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
@@ -3457,6 +3457,7 @@ extern int intel_opregion_notify_encoder(struct intel_encoder *intel_encoder,
 					 bool enable);
 extern int intel_opregion_notify_adapter(struct drm_device *dev,
 					 pci_power_t state);
+extern int intel_opregion_get_panel_type(struct drm_device *dev);
 #else
 static inline int intel_opregion_setup(struct drm_device *dev) { return 0; }
 static inline void intel_opregion_init(struct drm_device *dev) { return; }
@@ -3472,6 +3473,10 @@ intel_opregion_notify_adapter(struct drm_device *dev, pci_power_t state)
 {
 	return 0;
 }
+static inline int intel_opregion_get_panel_type(struct drm_device *dev)
+{
+	return -ENODEV;
+}
 #endif
 
 /* intel_acpi.c */
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
@@ -205,19 +205,29 @@ parse_lfp_panel_data(struct drm_i915_private *dev_priv,
 	struct drm_display_mode *panel_fixed_mode;
 	int panel_type;
 	int drrs_mode;
+	int ret;
 
 	lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
 	if (!lvds_options)
 		return;
 
 	dev_priv->vbt.lvds_dither = lvds_options->pixel_dither;
-	if (lvds_options->panel_type > 0xf) {
-		DRM_DEBUG_KMS("Invalid VBT panel type 0x%x\n",
-			      lvds_options->panel_type);
-		return;
+
+	ret = intel_opregion_get_panel_type(dev_priv->dev);
+	if (ret >= 0) {
+		WARN_ON(ret > 0xf);
+		panel_type = ret;
+		DRM_DEBUG_KMS("Panel type: %d (OpRegion)\n", panel_type);
+	} else {
+		if (lvds_options->panel_type > 0xf) {
+			DRM_DEBUG_KMS("Invalid VBT panel type 0x%x\n",
+				      lvds_options->panel_type);
+			return;
+		}
+		panel_type = lvds_options->panel_type;
+		DRM_DEBUG_KMS("Panel type: %d (VBT)\n", panel_type);
 	}
 
-	panel_type = lvds_options->panel_type;
 	dev_priv->vbt.panel_type = panel_type;
 
 	drrs_mode = (lvds_options->dps_panel_type_bits
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
@@ -1024,3 +1024,31 @@ int intel_opregion_setup(struct drm_device *dev)
 	memunmap(base);
 	return err;
 }
+
+int
+intel_opregion_get_panel_type(struct drm_device *dev)
+{
+	u32 panel_details;
+	int ret;
+
+	ret = swsci(dev, SWSCI_GBDA_PANEL_DETAILS, 0x0, &panel_details);
+	if (ret) {
+		DRM_DEBUG_KMS("Failed to get panel details from OpRegion (%d)\n",
+			      ret);
+		return ret;
+	}
+
+	ret = (panel_details >> 8) & 0xff;
+	if (ret > 0x10) {
+		DRM_DEBUG_KMS("Invalid OpRegion panel type 0x%x\n", ret);
+		return -EINVAL;
+	}
+
+	/* fall back to VBT panel type? */
+	if (ret == 0x0) {
+		DRM_DEBUG_KMS("No panel type in OpRegion\n");
+		return -ENODEV;
+	}
+
+	return ret - 1;
+}
