From 05197921ff3dad52d99fd1647974c57d9c28d40e Mon Sep 17 00:00:00 2001 From: Edward Shao Date: Thu, 11 Feb 2010 03:37:30 +0800 Subject: [PATCH] USB: xhci: Fix finding extended capabilities registers According "5.3.6 Capability Parameters (HCCPARAMS)" of xHCI rev0.96 spec, value of xECP register indicates a relative offset, in 32-bit words, from Base to the beginning of the first extended capability. The wrong calculation will cause BIOS handoff fail (not handoff from BIOS) in some platform with BIOS USB legacy sup support. Signed-off-by: Edward Shao Cc: Sarah Sharp Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ext-caps.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci-ext-caps.h b/drivers/usb/host/xhci-ext-caps.h index ecc131c..78c4eda 100644 --- a/drivers/usb/host/xhci-ext-caps.h +++ b/drivers/usb/host/xhci-ext-caps.h @@ -101,12 +101,15 @@ static inline int xhci_find_next_cap_offset(void __iomem *base, int ext_offset) next = readl(base + ext_offset); - if (ext_offset == XHCI_HCC_PARAMS_OFFSET) + if (ext_offset == XHCI_HCC_PARAMS_OFFSET) { /* Find the first extended capability */ next = XHCI_HCC_EXT_CAPS(next); - else + ext_offset = 0; + } else { /* Find the next extended capability */ next = XHCI_EXT_CAPS_NEXT(next); + } + if (!next) return 0; /* -- 2.7.4