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

4 files changed, 46 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f2326fc60ac9..6f514297c483 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1856,10 +1856,16 @@
 #define CRT_HOTPLUG_DETECT_VOLTAGE_475MV	(1 << 2)
 
 #define PORT_HOTPLUG_STAT	(dev_priv->info->display_mmio_offset + 0x61114)
-/* HDMI/DP bits are gen4+ */
-#define   PORTB_HOTPLUG_LIVE_STATUS               (1 << 29)
+/*
+ * HDMI/DP bits are gen4+
+ *
+ * WARNING: Bspec for hpd status bits on gen4 seems to be completely confused.
+ * Please check the detailed lore in the commit message for for experimental
+ * evidence.
+ */
+#define   PORTD_HOTPLUG_LIVE_STATUS               (1 << 29)
 #define   PORTC_HOTPLUG_LIVE_STATUS               (1 << 28)
-#define   PORTD_HOTPLUG_LIVE_STATUS               (1 << 27)
+#define   PORTB_HOTPLUG_LIVE_STATUS               (1 << 27)
 #define   PORTD_HOTPLUG_INT_STATUS		(3 << 21)
 #define   PORTC_HOTPLUG_INT_STATUS		(3 << 19)
 #define   PORTB_HOTPLUG_INT_STATUS		(3 << 17)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5fb305840db8..e38b45786653 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8269,9 +8269,11 @@ check_crtc_state(struct drm_device *dev)
 
 		list_for_each_entry(encoder, &dev->mode_config.encoder_list,
 				    base.head) {
+			enum pipe pipe;
 			if (encoder->base.crtc != &crtc->base)
 				continue;
-			if (encoder->get_config)
+			if (encoder->get_config &&
+			    encoder->get_hw_state(encoder, &pipe))
 				encoder->get_config(encoder, &pipe_config);
 		}
 
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 67e2c1f1c9a8..5950888ae1d0 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -497,8 +497,11 @@ void intel_panel_set_backlight(struct drm_device *dev, u32 level, u32 max)
 		goto out;
 	}
 
-	/* scale to hardware */
-	level = level * freq / max;
+	/* scale to hardware, but be careful to not overflow */
+	if (freq < max)
+		level = level * freq / max;
+	else
+		level = freq / max * level;
 
 	dev_priv->backlight.level = level;
 	if (dev_priv->backlight.device)
@@ -515,6 +518,17 @@ void intel_panel_disable_backlight(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	unsigned long flags;
 
+	/*
+	 * Do not disable backlight on the vgaswitcheroo path. When switching
+	 * away from i915, the other client may depend on i915 to handle the
+	 * backlight. This will leave the backlight on unnecessarily when
+	 * another client is not activated.
+	 */
+	if (dev->switch_power_state == DRM_SWITCH_POWER_CHANGING) {
+		DRM_DEBUG_DRIVER("Skipping backlight disable on vga switch\n");
+		return;
+	}
+
 	spin_lock_irqsave(&dev_priv->backlight.lock, flags);
 
 	dev_priv->backlight.enabled = false;
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);
 		}
 	}
 }