ACPI: Populate DIDL before registering ACPI video device on Intel

Intel graphics hardware that implements the ACPI IGD OpRegion spec
requires that the list of display devices be populated before any ACPI
video methods are called. Detect when this is the case and defer
registration until the opregion code calls it. Fixes crashes on HP
laptops.

http://bugzilla.kernel.org/show_bug.cgi?id=11259

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 64 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_opregion.c b/drivers/gpu/drm/i915/i915_opregion.c
index ff012835a386..69427722d20e 100644
--- a/drivers/gpu/drm/i915/i915_opregion.c
+++ b/drivers/gpu/drm/i915/i915_opregion.c
@@ -26,6 +26,7 @@
  */
 
 #include <linux/acpi.h>
+#include <acpi/video.h>
 
 #include "drmP.h"
 #include "i915_drm.h"
@@ -136,6 +137,12 @@ struct opregion_asle {
 
 #define ASLE_CBLV_VALID         (1<<31)
 
+#define ACPI_OTHER_OUTPUT (0<<8)
+#define ACPI_VGA_OUTPUT (1<<8)
+#define ACPI_TV_OUTPUT (2<<8)
+#define ACPI_DIGITAL_OUTPUT (3<<8)
+#define ACPI_LVDS_OUTPUT (4<<8)
+
 static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -282,7 +289,58 @@ static struct notifier_block intel_opregion_notifier = {
 	.notifier_call = intel_opregion_video_event,
 };
 
-int intel_opregion_init(struct drm_device *dev)
+/*
+ * Initialise the DIDL field in opregion. This passes a list of devices to
+ * the firmware. Values are defined by section B.4.2 of the ACPI specification
+ * (version 3)
+ */
+
+static void intel_didl_outputs(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_opregion *opregion = &dev_priv->opregion;
+	struct drm_connector *connector;
+	int i = 0;
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		int output_type = ACPI_OTHER_OUTPUT;
+		if (i >= 8) {
+			dev_printk (KERN_ERR, &dev->pdev->dev,
+				    "More than 8 outputs detected\n");
+			return;
+		}
+		switch (connector->connector_type) {
+		case DRM_MODE_CONNECTOR_VGA:
+		case DRM_MODE_CONNECTOR_DVIA:
+			output_type = ACPI_VGA_OUTPUT;
+			break;
+		case DRM_MODE_CONNECTOR_Composite:
+		case DRM_MODE_CONNECTOR_SVIDEO:
+		case DRM_MODE_CONNECTOR_Component:
+		case DRM_MODE_CONNECTOR_9PinDIN:
+			output_type = ACPI_TV_OUTPUT;
+			break;
+		case DRM_MODE_CONNECTOR_DVII:
+		case DRM_MODE_CONNECTOR_DVID:
+		case DRM_MODE_CONNECTOR_DisplayPort:
+		case DRM_MODE_CONNECTOR_HDMIA:
+		case DRM_MODE_CONNECTOR_HDMIB:
+			output_type = ACPI_DIGITAL_OUTPUT;
+			break;
+		case DRM_MODE_CONNECTOR_LVDS:
+			output_type = ACPI_LVDS_OUTPUT;
+			break;
+		}
+		opregion->acpi->didl[i] |= (1<<31) | output_type | i;
+		i++;
+	}
+
+	/* If fewer than 8 outputs, the list must be null terminated */
+	if (i < 8)
+		opregion->acpi->didl[i] = 0;
+}
+
+int intel_opregion_init(struct drm_device *dev, int resume)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_opregion *opregion = &dev_priv->opregion;
@@ -312,6 +370,11 @@ int intel_opregion_init(struct drm_device *dev)
 	if (mboxes & MBOX_ACPI) {
 		DRM_DEBUG("Public ACPI methods supported\n");
 		opregion->acpi = base + OPREGION_ACPI_OFFSET;
+		if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+			intel_didl_outputs(dev);
+			if (!resume)
+				acpi_video_register();
+		}
 	} else {
 		DRM_DEBUG("Public ACPI methods not supported\n");
 		err = -ENOTSUPP;