From a3573ba9b18e2f20a12282e892f3a29cfe95d5d0 Mon Sep 17 00:00:00 2001
From: David Woodhouse <dwmw2@infradead.org>
Date: Fri, 13 Feb 2009 23:18:03 +0000
Subject: [PATCH] --- yaml --- r: 131360 b: refs/heads/master c:
 ca77fde8e62cecb2c0769052228d15b901367af8 h: refs/heads/master v: v3

---
 [refs]                          |  2 +-
 trunk/drivers/pci/intel-iommu.c | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index c7f73f4dc916..e66e1f410689 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1a88b5364b535edaa321d70a566e358390ff0872
+refs/heads/master: ca77fde8e62cecb2c0769052228d15b901367af8
diff --git a/trunk/drivers/pci/intel-iommu.c b/trunk/drivers/pci/intel-iommu.c
index f4b7c79023ff..fa9e41626bfc 100644
--- a/trunk/drivers/pci/intel-iommu.c
+++ b/trunk/drivers/pci/intel-iommu.c
@@ -61,6 +61,8 @@
 /* global iommu list, set NULL for ignored DMAR units */
 static struct intel_iommu **g_iommus;
 
+static int rwbf_quirk = 0;
+
 /*
  * 0: Present
  * 1-11: Reserved
@@ -785,7 +787,7 @@ static void iommu_flush_write_buffer(struct intel_iommu *iommu)
 	u32 val;
 	unsigned long flag;
 
-	if (!cap_rwbf(iommu->cap))
+	if (!rwbf_quirk && !cap_rwbf(iommu->cap))
 		return;
 	val = iommu->gcmd | DMA_GCMD_WBF;
 
@@ -3137,3 +3139,13 @@ static struct iommu_ops intel_iommu_ops = {
 	.unmap		= intel_iommu_unmap_range,
 	.iova_to_phys	= intel_iommu_iova_to_phys,
 };
+
+static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)
+{
+	/* Mobile 4 Series Chipset neglects to set RWBF capability,
+	   but needs it */
+	printk(KERN_INFO "DMAR: Forcing write-buffer flush capability\n");
+	rwbf_quirk = 1;
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf);