ACPI / i915: ignore firmware requests for backlight change

[karo-tx-linux.git] / drivers / gpu / drm / i915 / intel_opregion.c

diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index 2e2c71fcc9ed502dc3a013089d53a3270999ad51..4f6b53998d79652dafca7ea7e7f609a1d35eaca6 100644 (file)
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -403,6 +403,15 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
 
        DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
 
+       /*
+        * If the acpi_video interface is not supposed to be used, don't
+        * bother processing backlight level change requests from firmware.
+        */
+       if (!acpi_video_verify_backlight_support()) {
+               DRM_DEBUG_KMS("opregion backlight request ignored\n");
+               return 0;
+       }
+
        if (!(bclp & ASLE_BCLP_VALID))
                return ASLC_BACKLIGHT_FAILED;