dmaengine: ioatdma: workaround SKX ioatdma version

[ Upstream commit 34a31f0a ]

The Skylake ioatdma is technically CBDMA 3.2+ and contains the same hardware
bits with some additional 3.3 features, but it's not really 3.3 where the
driver is concerned.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/dma/ioat/init.c

@@ -1357,6 +1357,8 @@ static int ioat_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	device->version = readb(device->reg_base + IOAT_VER_OFFSET);
 	if (device->version >= IOAT_VER_3_0) {
+		if (is_skx_ioat(pdev))
+			device->version = IOAT_VER_3_2;
 		err = ioat3_dma_probe(device, ioat_dca_enabled);
 
 		if (device->version >= IOAT_VER_3_3)