From 006d5820b41b298328e6b6085e4d58129fbc78f0 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Thu, 29 Jul 2010 22:13:22 -0700 Subject: [PATCH] USB: xhci: Set DMA mask for host. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-pci.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 11482b6b9381..f7efe025beda 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -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); -- 2.20.1