Merge tag 'drm-intel-fixes-2013-08-08' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes

Daniel writes:
A few bugfixes for serious stuff and regressions. Highlight is the
reinstated hack to keep the i915 backlight on when running on an optimus
machine, this prevents black screens especially with some radeon muxed
platforms. And the patch to quiet dmesg on Linus' old mac mini ;-)

* tag 'drm-intel-fixes-2013-08-08' of git://people.freedesktop.org/~danvet/drm-intel:
  drm/i915: do not disable backlight on vgaswitcheroo switch off
  drm/i915: Don't call encoder's get_config unless encoder is active
  drm/i915: avoid brightness overflow when doing scale
  drm/i915: update last_vblank when disabling the power well
  drm/i915: fix gen4 digital port hotplug definitions

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f895d1508df8..b0e4a0bd1313 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5063,8 +5063,26 @@ static void __intel_set_power_well(struct drm_device *dev, bool enable)
                 }
         } else {
                 if (enable_requested) {
+                        unsigned long irqflags;
+                        enum pipe p;
+
                         I915_WRITE(HSW_PWR_WELL_DRIVER, 0);
+                        POSTING_READ(HSW_PWR_WELL_DRIVER);
                         DRM_DEBUG_KMS("Requesting to disable the power well\n");
+
+                        /*
+                         * After this, the registers on the pipes that are part
+                         * of the power well will become zero, so we have to
+                         * adjust our counters according to that.
+                         *
+                         * FIXME: Should we do this in general in
+                         * drm_vblank_post_modeset?
+                         */
+                        spin_lock_irqsave(&dev->vbl_lock, irqflags);
+                        for_each_pipe(p)
+                                if (p != PIPE_A)
+                                        dev->last_vblank[p] = 0;
+                        spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
                 }
         }
 }