From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 25 May 2012 05:17:06 +0000 (+0900)
Subject: 3.0-stable patches
X-Git-Tag: v3.0.33~19
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6e5ebb7ea96b06016f69232ab6dcdc2f5a3e0c5b;p=thirdparty%2Fkernel%2Fstable-queue.git

3.0-stable patches

added patches:
	drm-i915-avoid-a-double-read-of-pch_iir-during-interrupt-handling.patch
---

diff --git a/queue-3.0/drm-i915-avoid-a-double-read-of-pch_iir-during-interrupt-handling.patch b/queue-3.0/drm-i915-avoid-a-double-read-of-pch_iir-during-interrupt-handling.patch
new file mode 100644
index 00000000000..897674cf941
--- /dev/null
+++ b/queue-3.0/drm-i915-avoid-a-double-read-of-pch_iir-during-interrupt-handling.patch
@@ -0,0 +1,60 @@
+From 9adab8b5a7fde248504f484e197589f3e3c922e2 Mon Sep 17 00:00:00 2001
+From: Chris Wilson <chris@chris-wilson.co.uk>
+Date: Wed, 9 May 2012 21:45:43 +0100
+Subject: drm/i915: Avoid a double-read of PCH_IIR during interrupt handling
+
+From: Chris Wilson <chris@chris-wilson.co.uk>
+
+commit 9adab8b5a7fde248504f484e197589f3e3c922e2 upstream.
+
+Currently the code re-reads PCH_IIR during the hotplug interrupt
+processing. Not only is this a wasted read, but introduces a potential
+for handling a spurious interrupt as we then may not clear all the
+interrupts processed (since the re-read IIR may contains more interrupts
+asserted than we clear using the result of the original read).
+
+Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
+Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
+Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/gpu/drm/i915/i915_irq.c |    9 +++------
+ 1 file changed, 3 insertions(+), 6 deletions(-)
+
+--- a/drivers/gpu/drm/i915/i915_irq.c
++++ b/drivers/gpu/drm/i915/i915_irq.c
+@@ -422,14 +422,11 @@ static void gen6_pm_rps_work(struct work
+ 	mutex_unlock(&dev_priv->dev->struct_mutex);
+ }
+ 
+-static void pch_irq_handler(struct drm_device *dev)
++static void pch_irq_handler(struct drm_device *dev, u32 pch_iir)
+ {
+ 	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+-	u32 pch_iir;
+ 	int pipe;
+ 
+-	pch_iir = I915_READ(SDEIIR);
+-
+ 	if (pch_iir & SDE_AUDIO_POWER_MASK)
+ 		DRM_DEBUG_DRIVER("PCH audio power change on port %d\n",
+ 				 (pch_iir & SDE_AUDIO_POWER_MASK) >>
+@@ -527,7 +524,7 @@ static irqreturn_t ivybridge_irq_handler
+ 	if (de_iir & DE_PCH_EVENT_IVB) {
+ 		if (pch_iir & SDE_HOTPLUG_MASK_CPT)
+ 			queue_work(dev_priv->wq, &dev_priv->hotplug_work);
+-		pch_irq_handler(dev);
++		pch_irq_handler(dev, pch_iir);
+ 	}
+ 
+ 	if (pm_iir & GEN6_PM_DEFERRED_EVENTS) {
+@@ -626,7 +623,7 @@ static irqreturn_t ironlake_irq_handler(
+ 	if (de_iir & DE_PCH_EVENT) {
+ 		if (pch_iir & hotplug_mask)
+ 			queue_work(dev_priv->wq, &dev_priv->hotplug_work);
+-		pch_irq_handler(dev);
++		pch_irq_handler(dev, pch_iir);
+ 	}
+ 
+ 	if (de_iir & DE_PCU_EVENT) {
diff --git a/queue-3.0/series b/queue-3.0/series
index 0c2567c2363..6cd6afb137d 100644
--- a/queue-3.0/series
+++ b/queue-3.0/series
@@ -44,3 +44,4 @@ usb-xhci-handle-comp_tx_err-for-isoc-tds.patch
 xhci-reset-reserved-command-ring-trbs-on-cleanup.patch
 xhci-add-new-short-tx-quirk-for-fresco-logic-host.patch
 usbcore-enable-usb2-lpm-if-port-suspend-fails.patch
+drm-i915-avoid-a-double-read-of-pch_iir-during-interrupt-handling.patch