[PATCH v1 1/2] usb:dwc3: Enable support for 64-bit system
From: Thang Q. Nguyen
Date: Thu Jan 14 2016 - 00:09:45 EST
Add 64-bit DMA operation support to the USB DWC3 driver.
First attempt to set the coherent DMA mask for 64-bit DMA.
If that failed, attempt again with 32-bit DMA.
Signed-off-by: Thang Q. Nguyen <tqnguyen@xxxxxxx>
---
drivers/usb/dwc3/core.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 22b47973..9818d6b 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -829,6 +829,21 @@ static int dwc3_probe(struct platform_device *pdev)
dwc->mem = mem;
dwc->dev = dev;
+ /* Try to set 64-bit DMA first */
+ if (WARN_ON(!pdev->dev.dma_mask))
+ /* Platform did not initialize dma_mask */
+ ret = dma_coerce_mask_and_coherent(&pdev->dev,
+ DMA_BIT_MASK(64));
+ else
+ ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+
+ /* If seting 64-bit DMA mask fails, fall back to 32-bit DMA mask */
+ if (ret) {
+ ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ if (ret)
+ return ret;
+ }
+
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_err(dev, "missing IRQ\n");
--
2.2.0