drm/i915: add debug logging to ASLE backlight set requests

Make it easier to track backlight set requests coming through ASLE instead
of the driver's own backlight sysfs interface. We've had enough of
backlight issues to warrant some extra debug logs in the area.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index e27c1701262824bfc167c83db4b7f36481e01f76..0f2db1648f04e6a328b459b604ed7b9f3986dd73 100644 (file)
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -154,6 +154,8 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
        struct opregion_asle __iomem *asle = dev_priv->opregion.asle;
        u32 max;
 
+       DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
+
        if (!(bclp & ASLE_BCLP_VALID))
                return ASLE_BACKLIGHT_FAILED;