From: AMEET M. PARANJAPE <aparanja@redhat.com>
Date: Mon, 8 Jun 2009 16:08:42 -0400
Subject: [scsi] ipr: fix PCI permanent error handler
Message-id: 20090608200528.23882.84166.sendpatchset@squad5-lp1.lab.bos.redhat.com
O-Subject: [PATCH RHEL5.4 BZ503960] ipr: fix PCI permanent error handler
Bugzilla: 503960
RH-Acked-by: Pete Zaitcev <zaitcev@redhat.com>
RH-Acked-by: Mike Christie <mchristi@redhat.com>
RH-Acked-by: Stefan Assmann <sassmann@redhat.com>
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>
RH-Acked-by: David Howells <dhowells@redhat.com>

RHBZ#:
======
https://bugzilla.redhat.com/show_bug.cgi?id=503960

Description:
===========
The ipr driver can hang if it encounters enough PCI errors
to trigger the permanent error handler. The driver will attempt
to initiate a "bringdown" of the adapter and fail all pending
ops back.

In this code path, we end up failing back with allow_cmds still set to 1.
This results in some commands getting immediately re-issued to the adapter
on the done call, which results in an infinite loop in ipr_fail_all_ops.
Fix this by setting allow_cmds to zero in this path.

RHEL Version Found:
================
RHEL 5.3

kABI Status:
============
No symbols were harmed.

Brew:
=====
Built on all platforms.
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1831949

Upstream Status:
================
http://git.kernel.org/?p=linux/kernel/git/jejb/scsi-misc-2.6.git;a=commit;h=6e145ad73987cfc8375e5396073dd2692e07bd15

Test Status:
============
A testcase is given in the Bugzilla.  Without the patch a PPC box with IPR
device will hang when trying to remove ipr module after the 6th EEH error
inject.

With this patch the hang is not seen.
===============================================================
Ameet Paranjape 978-392-3903 ext 23903
IBM on-site partner

Proposed Patch:
===============

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index b6fec36..63049ce 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -7045,6 +7045,7 @@ static void ipr_pci_perm_failure(struct pci_dev *pdev)
 		ioa_cfg->sdt_state = ABORT_DUMP;
 	ioa_cfg->reset_retries = IPR_NUM_RESET_RELOAD_RETRIES;
 	ioa_cfg->in_ioa_bringdown = 1;
+	ioa_cfg->allow_cmds = 0;
 	ipr_initiate_ioa_reset(ioa_cfg, IPR_SHUTDOWN_NONE);
 	spin_unlock_irqrestore(ioa_cfg->host->host_lock, flags);
 }