X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Fgpu%2Fdrm%2Fi915%2Fintel_opregion.c;h=4f6b53998d79652dafca7ea7e7f609a1d35eaca6;hb=bcf44bfe5e929468b781082889d4b17245aff3ca;hp=2e2c71fcc9ed502dc3a013089d53a3270999ad51;hpb=682b7c1c8ea8885aa681ddf530d6cf2ad4f2dc15;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index 2e2c71fcc9ed..4f6b53998d79 100644
--- 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;