From 142587887e28e8f71bbb3bb7eacdf7f2d7f8a10b Mon Sep 17 00:00:00 2001
From: Thomas Jarosch <thomas.jarosch@intra2net.com>
Date: Wed, 7 Dec 2011 22:08:11 +0100
Subject: [PATCH] --- yaml --- r: 294720 b: refs/heads/master c:
 f67fd55fa96f7d7295b43ffbc4a97d8f55e473aa h: refs/heads/master v: v3

---
 [refs]                     |  2 +-
 trunk/drivers/pci/quirks.c | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 05da2b97a5c2..fdcaa1ce8a14 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3209874a1da2c51c7325e601d9634189ee178ad6
+refs/heads/master: f67fd55fa96f7d7295b43ffbc4a97d8f55e473aa
diff --git a/trunk/drivers/pci/quirks.c b/trunk/drivers/pci/quirks.c
index f5d09f4066f3..fb544d6d29f6 100644
--- a/trunk/drivers/pci/quirks.c
+++ b/trunk/drivers/pci/quirks.c
@@ -2924,6 +2924,40 @@ static void do_one_fixup_debug(void (*fn)(struct pci_dev *dev), struct pci_dev *
 		duration);
 }
 
+/*
+ * Some BIOS implementations leave the Intel GPU interrupts enabled,
+ * even though no one is handling them (f.e. i915 driver is never loaded).
+ * Additionally the interrupt destination is not set up properly
+ * and the interrupt ends up -somewhere-.
+ *
+ * These spurious interrupts are "sticky" and the kernel disables
+ * the (shared) interrupt line after 100.000+ generated interrupts.
+ *
+ * Fix it by disabling the still enabled interrupts.
+ * This resolves crashes often seen on monitor unplug.
+ */
+#define I915_DEIER_REG 0x4400c
+static void __devinit disable_igfx_irq(struct pci_dev *dev)
+{
+	void __iomem *regs = pci_iomap(dev, 0, 0);
+	if (regs == NULL) {
+		dev_warn(&dev->dev, "igfx quirk: Can't iomap PCI device\n");
+		return;
+	}
+
+	/* Check if any interrupt line is still enabled */
+	if (readl(regs + I915_DEIER_REG) != 0) {
+		dev_warn(&dev->dev, "BIOS left Intel GPU interrupts enabled; "
+			"disabling\n");
+
+		writel(0, regs + I915_DEIER_REG);
+	}
+
+	pci_iounmap(dev, regs);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0102, disable_igfx_irq);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x010a, disable_igfx_irq);
+
 static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
 			  struct pci_fixup *end)
 {