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 <laface.tw@gmail.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Edward Shao 2010-02-11 03:37:30 +08:00 committed by Greg Kroah-Hartman
parent cceffe9348
commit 05197921ff

View file

@ -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;
/*