From: Duc Dang Date: Fri, 9 Oct 2015 10:30:11 +0000 (+0300) Subject: usb: make xhci platform driver use 64 bit or 32 bit DMA X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0ebbe398f68be0d9bbd41dcfb57319e697756b37;p=linux-beck.git 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 Tested-by: Mark Salter Signed-off-by: Duc Dang Acked-by: Arnd Bergmann Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 890ad9d9d329..34c93e87b2d3 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -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)