Commit 228c4f5c authored by Dan Williams's avatar Dan Williams
Browse files

ioat3: dca and raid operations are incompatible 



RAID operations cause a system hang on platforms with DCA
(Direct-Cache-Access) enabled.  So turn off RAID capabilities in this
case.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent e22dde99

drivers/dma/ioat/dca.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

drivers/dma/ioat/dma_v3.c

+6 −0
Original line number Diff line number Diff line
@@ -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;

drivers/dma/ioat/hw.h

+2 −0
Original line number Diff line number Diff line
@@ -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 {