From: Mark Langsdorf Date: Wed, 25 Mar 2015 14:12:51 -0400 Subject: [PATCH] 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. Signed-off-by: Mark Langsdorf --- drivers/usb/host/xhci-plat.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 0e11d61408ff..cc5ca2cac706 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -83,14 +83,13 @@ 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; - else - dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)); + /* Try setting the coherent_dma_mask to 64 bits, then try 32 bits */ + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); + 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) -- 2.1.0