[PATCH 1/2] [usb] make xhci platform driver use 64 bit or 32 bit DMA
From: Mark Langsdorf <hidden>
Date: 2014-10-30 18:16:28
Subsystem:
the rest, usb subsystem, usb xhci driver · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Mathias Nyman
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 <redacted> --- drivers/usb/host/xhci-plat.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 1a0cf9f..3045e77 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c@@ -147,14 +147,17 @@ static int xhci_plat_probe(struct platform_device *pdev) return ret; } - /* 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 the coherent_dma_mask to 64 bits, then try 32 bits */ + if (sizeof(dma_addr_t) < 8 || + dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64))) { + 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)); + dma_set_mask(&pdev->dev, pdev->dev.coherent_dma_mask); hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev)); if (!hcd)
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1.9.3