Red Hat Bugzilla – Bug 651332
RHEL6.1: EHCI: AMD periodic frame list table quirk
Last modified: 2015-01-04 17:59:54 EST
On AMD SB700/SB800/Hudson-2/3 platforms, USB EHCI controller may read/write to memory space not allocated to USB controller if there is longer than normal latency on DMA read encountered. In this condition the exposure will be encountered only if the driver has following format of Periodic Frame List link pointer structure: For any idle periodic schedule, the Frame List link pointers that have the T-bit set to 1 intending to terminate the use of frame list link pointer as a physical memory pointer. Idle periodic schedule Frame List Link pointer shoule be in the following format to avoid the issue: Frame list link pointer should be always contains a valid pointer to a inactive QHead with T-bit set to 0. Steps to Reproduce: It is SW workaround of HW issue, it is difficult to reproduce from driver point. Patch has been accepted by EHCI maintainer: http://www.spinics.net/lists/linux-usb/msg38405.html http://www.spinics.net/lists/linux-usb/msg38414.html
We will provide the git link here once it is available, suppose the patch will appear from kernel 2.6.37 if everything is ok.
Created attachment 462284 [details] ehci_frame_list_fix_RHEL6.patch
Please find the patch attached.
I haven't seen this patch make it upstream? Is it queued for 2.6.38 instead? Cheers, Don
Here is the git link, which will appear from 2.6.37: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3d091a6f703906c5680855ff29bd94d051c8c6d8 Please help to add it into RHEL6.x kernel, thanks
Ok. thanks. I have no idea how I missed that when I was looking through the upstream changelogs. Cheers, Don
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
Patch(es) available on kernel-2.6.32-112.el6
Verified OK with kernel-2.6.32-112.el6 x86_64
Verified in 2.6.32-128.el6.x86_64.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0542.html