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path: root/drivers/gpu/drm/i915/intel_opregion.c
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Diffstat (limited to 'drivers/gpu/drm/i915/intel_opregion.c')
-rw-r--r--drivers/gpu/drm/i915/intel_opregion.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index 5cc624eb613..5530413213d 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -427,6 +427,25 @@ blind_set:
goto end;
}
+static void intel_setup_cadls(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_opregion *opregion = &dev_priv->opregion;
+ int i = 0;
+ u32 disp_id;
+
+ /* Initialize the CADL field by duplicating the DIDL values.
+ * Technically, this is not always correct as display outputs may exist,
+ * but not active. This initialization is necessary for some Clevo
+ * laptops that check this field before processing the brightness and
+ * display switching hotkeys. Just like DIDL, CADL is NULL-terminated if
+ * there are less than eight devices. */
+ do {
+ disp_id = ioread32(&opregion->acpi->didl[i]);
+ iowrite32(disp_id, &opregion->acpi->cadl[i]);
+ } while (++i < 8 && disp_id != 0);
+}
+
void intel_opregion_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -436,8 +455,10 @@ void intel_opregion_init(struct drm_device *dev)
return;
if (opregion->acpi) {
- if (drm_core_check_feature(dev, DRIVER_MODESET))
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
intel_didl_outputs(dev);
+ intel_setup_cadls(dev);
+ }
/* Notify BIOS we are ready to handle ACPI video ext notifs.
* Right now, all the events are handled by the ACPI video module.