drm/i915: Clear pfit registers when not used by any outputs
... otherwise the panel-fitter may be left enabled with random settings
and cause unintended filtering (i.e. blurring of native modes on external
panels).
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31942
Reported-and-tested-by: Ben Kohler <bkohler@gmail.com>
Tested-by: Ciprian Docan <docan@eden.rutgers.edu>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bee24b1..255b52e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5336,9 +5336,14 @@
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_encoder *encoder;
bool dpd_is_edp = false;
+ bool has_lvds = false;
if (IS_MOBILE(dev) && !IS_I830(dev))
- intel_lvds_init(dev);
+ has_lvds = intel_lvds_init(dev);
+ if (!has_lvds && !HAS_PCH_SPLIT(dev)) {
+ /* disable the panel fitter on everything but LVDS */
+ I915_WRITE(PFIT_CONTROL, 0);
+ }
if (HAS_PCH_SPLIT(dev)) {
dpd_is_edp = intel_dpd_is_edp(dev);