[PATCH v8 3/3] usb: xhci: configure 32-bit DMA if the controller does not support 64-bit DMA
From: Duc Dang <hidden>
Date: 2015-09-17 18:23:14
Also in:
lkml
Subsystem:
the rest, usb subsystem, usb xhci driver · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Mathias Nyman
This change avoids DMA error in the cases where dma_mask and coherent_dma_mask of a 32-bit controller get configured as DMA_BIT_MASK(64) when running on a 64-bit system. Signed-off-by: Duc Dang <redacted> --- drivers/usb/host/xhci.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6b0f4a4..8cb8f39 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c@@ -4908,6 +4908,16 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks) !dma_set_mask(dev, DMA_BIT_MASK(64))) { xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n"); dma_set_coherent_mask(dev, DMA_BIT_MASK(64)); + } else { + /* + * This is to avoid error in cases where a 32-bit USB + * controller is used on a 64-bit capable system. + */ + retval = dma_set_mask(dev, DMA_BIT_MASK(32)); + if (retval) + return retval; + xhci_dbg(xhci, "Enabling 32-bit DMA addresses.\n"); + dma_set_coherent_mask(dev, DMA_BIT_MASK(32)); } xhci_dbg(xhci, "Calling HCD init\n");
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1.9.1