-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
USB: xhci: Represent 64-bit addresses with one u64.
There are several xHCI data structures that use two 32-bit fields to represent a 64-bit address. Since some architectures don't support 64-bit PCI writes, the fields need to be written in two 32-bit writes. The xHCI specification says that if a platform is incapable of generating 64-bit writes, software must write the low 32-bits first, then the high 32-bits. Hardware that supports 64-bit addressing will wait for the high 32-bit write before reading the revised value, and hardware that only supports 32-bit writes will ignore the high 32-bit write. Previous xHCI code represented 64-bit addresses with two u32 values. This lead to buggy code that would write the 32-bits in the wrong order, or forget to write the upper 32-bits. Change the two u32s to one u64 and create a function call to write all 64-bit addresses in the proper order. This new function could be modified in the future if all platforms support 64-bit writes. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- Loading branch information
Sarah Sharp
authored and
Greg Kroah-Hartman
committed
Jul 28, 2009
1 parent
b11069f
commit 8e595a5
Showing
5 changed files
with
137 additions
and
148 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.