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 4.2-rc5 and address new comments] Signed-off-by: Mark Langsdorf <mlangsdo@xxxxxxxxxx> Tested-by: Mark Salter <msalter@xxxxxxxxxx> Signed-off-by: Duc Dang <dhdang@xxxxxxx> --- Changes from v5: -Change comment -Assign dma_mask to coherent_dma_mask if dma_mask is NULL to make sure dma_set_mask_and_coherent does not fail prematurely. Changes from v4: -None Changes from v3: -Re-generate the patch over 4.2-rc5 -No code change. Changes from v2: -None Changes from v1: -Consolidated to use dma_set_mask_and_coherent -Got rid of the check against sizeof(dma_addr_t) drivers/usb/host/xhci-plat.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 890ad9d..5d1b84b 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -93,14 +93,18 @@ 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; + /* + * Try setting dma_mask and coherent_dma_mask to 64 bits, + * then try 32 bits + */ if (!pdev->dev.dma_mask) pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; - else - dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)); + 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) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html