usb: make xhci platform driver use 64 bit or 32 bit DMA
The xhci platform driver needs to work on systems that
either only support 64-bit DMA or only support 32-bit DMA.
Attempt to set a coherent dma mask for 64-bit DMA, and
attempt again with 32-bit DMA if that fails.
[dhdang: regenerate the patch over v4.3-rc1 and address new comments]
Signed-off-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Duc Dang <dhdang@apm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 890ad9d..34c93e8 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -93,14 +93,20 @@
if (irq < 0)
return -ENODEV;
- /* Initialize dma_mask and coherent_dma_mask to 32-bits */
- ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
- if (ret)
- return ret;
- if (!pdev->dev.dma_mask)
- pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+ /* 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
- dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+ 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;
+ }
hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
if (!hcd)