drm/i915/lvds: Always use 0 to disable the pfit controller

... and just any combination of bits & ~PFIT_ENABLE. This way we do not
attempt disable to the panel fitter controller uselessly upon
intel_lvds_disable().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 4e7dcb330da..8f4f6bd33ee 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -374,6 +374,10 @@ static bool intel_lvds_mode_fixup(struct drm_encoder *encoder,
         }
 
 out:
+        if ((pfit_control & PFIT_ENABLE) == 0) {
+                pfit_control = 0;
+                pfit_pgm_ratios = 0;
+        }
         if (pfit_control != intel_lvds->pfit_control ||
             pfit_pgm_ratios != intel_lvds->pfit_pgm_ratios) {
                 intel_lvds->pfit_control = pfit_control;