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>
This commit is contained in:
Duc Dang 2015-10-09 13:30:11 +03:00 committed by Greg Kroah-Hartman
parent 8451a34ff6
commit 0ebbe398f6

View file

@ -93,14 +93,20 @@ static int xhci_plat_probe(struct platform_device *pdev)
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)