usb: make xhci platform driver use 64 bit or 32 bit DMA (0ebbe398) · Commits · 戴 / test

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>

drivers/usb/host/xhci-plat.c

+13 −7

Original line number	Diff line number	Diff line
		@@ -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));
		/* 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;
		if (!pdev->dev.dma_mask)
		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
		else
		dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
		}

		hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
		if (!hcd)

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