Red Hat Bugzilla – Bug 231768
[RHEL4] VIA EPIA-EK10000 does not reboot without PS/2 keyboard attached
Last modified: 2012-06-20 09:24:27 EDT
Description of problem:
VIA EPIA-EK10000 motherboard does not reboot if PS/2 keyboard is not attached.
Version-Release number of selected component (if applicable):
100% on all the system I have with this motherboard.
Steps to Reproduce:
1. Boot system without PS/2 keyboard attached
2. remote login to the system (either serial console, ssh)
3. # reboot
After the last printk message "Restarting system.", system does not reboot
Fedore Core 4 with 2.6.11 kernel exhibit the same problem but Fedora Core 5 with 2.6.15 kernel
reboot fine on those motherboards. Comparing the differences around the reboot code,
pulling in the single change to a inline function mach_reboot from 2.6.15 (or somewhere
between .11 and .15) into 2.6.9 resolved the reboot problem on those particular motherboard.
(please refer to the attached patch).
This may resolve the following bug too:
Reboot failure on AMD64 when no keyboard attached
Created attachment 149791 [details]
patch to pull in the fix from 2.6.15 kernel
Still issue with 2.6.9-55 in 4.6. My assumption is that this affect more than this particular
class of motherboard. Since it is such a safe and straight forward back merge from
the future version of kernel, I would appreciate if this is considered for 4.6 update.
To add credibility, I attached a reference to the original commit in 2.6.16 stable tree.
Created attachment 213701 [details]
patch based on commits
Hiroto, please test the kernel available in
or just apply the patch I've attached here and let me know the results.
I don't have any machine VIA based available. I suspect the new box I got at
home is VIA based. I'll check at night.
Thanks Aristeu. Unfortunately, that kernel didn't reboot.
I see that you pulled in the latest patch from 2.6.23-rc which
has some added logic about reading command control byte. That seems to
be not working out with my VIA MB for some reason.
Is it too much to ask to exclude the lastest change and just
apply the one in between?
Or I should figure out how to make this new code with VIA
and send in patch again 2.6.23-rc.
Do you know of any documentation in this area I can refer to.
I mailed Truxton Fulton, the original author of those patches for information.
Got response back from Mr. Fulton. After making the change he suggested, it rebooted
fine on my MB.
Do you mean that my original patch (59f4e7d572980a521b7bdba74ab71b21f5995538)
fixes your reboot problem, but the new patch (8b93789808756bcc1e5c90c99f1b1ef52f839a51)
does not work?
When I debugged this problem, I found that the keyboard controller
would refuse to pulse the reset low if there was no keyboard attached.
Forcing the system flag to 1 seemed to satisfy the VIA chip,
and the reboot could proceed.
I used google to find documentation for the AT keyboard controller.
Here are some links :
Unfortunately, I no longer have access to a machine with the
rebooting problem, so I was unable to verify that my second patch
worked for machines that could not reboot normally.
Perhaps the controller command byte need to have
_EN (Disable keyboard) also set (which is what the first patch did).
Can you please try changing this line :
outb(cmd | 0x04, 0x60); /* set "System flag" */
to this :
outb(cmd | 0x14, 0x60); /* set "System flag" and "Disable Keyboard" */
To see if that works for you?
Related kernel bugzilla entry. Mr. Fulton posted additional patch with above change
against 2.6.23-rc9 at the bottom.
I saw Truxton message on lkml. Before including the fix, I have to wait for it
to be included into Linus' tree. I've just checked for the fix and it's not
included yet. Do you need a new test kernel with this patch included?
I have tested it myself so I'm confident the patch itself is ok.
If you have to wait for commit in main tree anyway, and for me to test right now
will not speed up the process, I can wait.
It's on -mm but not pulled into Linus' tree yet.
The patch is upstream:
the test kernels are on:
please test and let me know how it goes.
Hmm, sorry to say that it didn't work, although commit 05dfa35e84331c6921ab394463069e9376f0bd76
looks good. Could you upload the source RPM so I can take a look?
the patch is linux-kernel-test.patch
It seems there's something else missing
Aristeu, you added the variable "cmd" as "int" while on the main line
it is "u8".
Since this is an include file with only two short inline functions defined,
and all we are doing is to patch it up to be identical to the latest,
isn't it easier to simply grab the copy of the latest and drop it in,
rather than hand edit the source?
Nope, upstream cmd is int.
Did you tried the last upstream version?
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