From 2e6c7d9b66e182ac3188c494ea94f797425fef05 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams@intel.com>
Date: Thu, 19 Nov 2009 17:07:10 -0700
Subject: [PATCH] --- yaml --- r: 168857 b: refs/heads/master c:
 228c4f5cfbf1cda411d9aa7204a612a63c89b1e8 h: refs/heads/master i:   168855:
 00d17ceb8454d72056d2c3e9e8077d3bf8c76feb v: v3

---
 [refs]                          | 2 +-
 trunk/drivers/dma/ioat/dca.c    | 2 +-
 trunk/drivers/dma/ioat/dma_v3.c | 6 ++++++
 trunk/drivers/dma/ioat/hw.h     | 2 ++
 4 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index a9d8592bdb92..6fa939e3eb4f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e22dde9904c2d26a522f1a2b89854a8238bf0933
+refs/heads/master: 228c4f5cfbf1cda411d9aa7204a612a63c89b1e8
diff --git a/trunk/drivers/dma/ioat/dca.c b/trunk/drivers/dma/ioat/dca.c
index 14f0a782df44..abd9038e06b1 100644
--- a/trunk/drivers/dma/ioat/dca.c
+++ b/trunk/drivers/dma/ioat/dca.c
@@ -103,7 +103,7 @@ static int dca_enabled_in_bios(struct pci_dev *pdev)
 	return res;
 }
 
-static int system_has_dca_enabled(struct pci_dev *pdev)
+int system_has_dca_enabled(struct pci_dev *pdev)
 {
 	if (boot_cpu_has(X86_FEATURE_DCA))
 		return dca_enabled_in_bios(pdev);
diff --git a/trunk/drivers/dma/ioat/dma_v3.c b/trunk/drivers/dma/ioat/dma_v3.c
index 35d1e33afd5b..4f305f61f878 100644
--- a/trunk/drivers/dma/ioat/dma_v3.c
+++ b/trunk/drivers/dma/ioat/dma_v3.c
@@ -1117,6 +1117,7 @@ static int __devinit ioat3_dma_self_test(struct ioatdma_device *device)
 int __devinit ioat3_dma_probe(struct ioatdma_device *device, int dca)
 {
 	struct pci_dev *pdev = device->pdev;
+	int dca_en = system_has_dca_enabled(pdev);
 	struct dma_device *dma;
 	struct dma_chan *c;
 	struct ioat_chan_common *chan;
@@ -1137,6 +1138,11 @@ int __devinit ioat3_dma_probe(struct ioatdma_device *device, int dca)
 	dma->device_prep_dma_interrupt = ioat3_prep_interrupt_lock;
 
 	cap = readl(device->reg_base + IOAT_DMA_CAP_OFFSET);
+
+	/* dca is incompatible with raid operations */
+	if (dca_en && (cap & (IOAT_CAP_XOR|IOAT_CAP_PQ)))
+		cap &= ~(IOAT_CAP_XOR|IOAT_CAP_PQ);
+
 	if (cap & IOAT_CAP_XOR) {
 		is_raid_device = true;
 		dma->max_xor = 8;
diff --git a/trunk/drivers/dma/ioat/hw.h b/trunk/drivers/dma/ioat/hw.h
index 99afb12bd409..60e675455b6a 100644
--- a/trunk/drivers/dma/ioat/hw.h
+++ b/trunk/drivers/dma/ioat/hw.h
@@ -39,6 +39,8 @@
 #define IOAT_VER_3_0            0x30    /* Version 3.0 */
 #define IOAT_VER_3_2            0x32    /* Version 3.2 */
 
+int system_has_dca_enabled(struct pci_dev *pdev);
+
 struct ioat_dma_descriptor {
 	uint32_t	size;
 	union {