Bug 157241 - [RHEL4-U3] PCI Hotplug - Slot powered off after enabling
[RHEL4-U3] PCI Hotplug - Slot powered off after enabling
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel (Show other bugs)
i686 Linux
medium Severity medium
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Assigned To: Keiichiro Tokunaga
Brian Brock
Depends On:
Blocks: 168429
  Show dependency treegraph
Reported: 2005-05-09 14:17 EDT by David Milburn
Modified: 2010-10-21 22:59 EDT (History)
4 users (show)

See Also:
Fixed In Version: RHSA-2006-0132
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2006-03-07 14:00:31 EST
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Regression: ---
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Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
Maintainer's patch recreated with gendiff (3.79 KB, patch)
2005-05-09 14:19 EDT, David Milburn
no flags Details | Diff

  None (edit)
Description David Milburn 2005-05-09 14:17:59 EDT
From Bugzilla Helper:
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Description of problem:
On the Fujitsu Primequest, echoing "1" to the "power" file of
an already-enabled slot will actually disable the slot. Fujitsu
has discussed this with the maintainer of the SHPC driver
(Dely L. Sy) who had developed a patch to correct the problem.
Fujitsu has verified the fix and would like it to be included 
in RHEL4.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1.Echo "1" to /sys/bus/pci/slots/X/power of an already enabled slot.

Actual Results:  The slot was powered off.

Expected Results:  Slot should not be powered off.

Additional info:

I didn't have access to hardware with a SHPC based PCI hotplug slot;
but, I did recreate the patch with gendiff and verify that it could
be applied to kernel-2.6.9-5.0.3.EL and compiled. The patch primarily
changes return values in shpchp_enable_slot() and shpchp_disable_slot().
Comment 1 David Milburn 2005-05-09 14:19:40 EDT
Created attachment 114172 [details]
Maintainer's patch recreated with gendiff
Comment 5 Keiichiro Tokunaga 2005-10-04 13:28:58 EDT
I have backported the maintainer's patch to the latest RHEL4 kernel and posted 
it to rhkernel-list yesterday.
Comment 6 Keiichiro Tokunaga 2005-10-07 17:36:34 EDT
I got an ACK in rhkernel-list today.
Comment 8 Keiichiro Tokunaga 2005-10-20 14:11:14 EDT
Here is an additional information.

I got another Ack in rhkernel-list the other day, so now there are
2 Acks from engineers.

By the way, here is an information about the patch and the testing
that I have done.  I have mentioned about them in rhkernel-list, but
it seems that I haven't mentioned much about them here.  A fix patch
for this problem, which the maintainer has created, has already been
in the mainstream.  I have backported it to the latest kernel of
RHEL4 and done test on a ia64 machine that has hotplug PCI slots.
Here is the results of the test.

  [root@primeq1 ~]# cat  /sys/bus/pci/slots/19/power
  [root@primeq1 ~]# echo 1 >  /sys/bus/pci/slots/19/power
  [root@primeq1 ~]# cat  /sys/bus/pci/slots/19/power
  [root@primeq1 ~]# cat /var/log/messages | tail -2
  Sep 30 10:52:18 primeq1 ntpd[4949]: kernel time sync disabled 0041
  Sep 30 10:52:49 primeq1 kernel: shpchp: shpchp_enable_slot: already enabled 
on slot(13)
Comment 15 Red Hat Bugzilla 2006-03-07 14:00:31 EST
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 the 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.


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