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USB: xhci: Set DMA mask for host.

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Tell the USB core that we can do DMA directly (instead of needing it to
memory-map the buffers for PIO).  If the xHCI host supports 64-bit addresses,
set the DMA mask accordingly.  Otherwise indicate the host can handle 32-bit DMA
addresses.

This improves performance because the USB core doesn't have to spend time
remapping buffers in high memory into the 32-bit address range.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Sarah Sharp 2010-07-29 22:13:22 -07:00 committed by Greg Kroah-Hartman
parent ed3f245392
commit 006d5820b4
1 changed files with 9 additions and 0 deletions
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9
drivers/usb/host/xhci-pci.c
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@ -53,6 +53,7 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
int retval;
u32 temp;
hcd->self.sg_tablesize = TRBS_PER_SEGMENT - 2;
@ -93,6 +94,14 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
return retval;
xhci_dbg(xhci, "Reset complete\n");
temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
if (HCC_64BIT_ADDR(temp)) {
xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n");
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(64));
} else {
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(32));
}
xhci_dbg(xhci, "Calling HCD init\n");
/* Initialize HCD and host controller data structures. */
retval = xhci_init(hcd);