From: Bruno Prémont <bonbons@linux-vserver.org>
Date: Fri, 19 Dec 2014 09:29:16 +0000 (+0100)
Subject: qla2xxx: fix busy wait regression
X-Git-Tag: fixes-v4.0-rc1~319^2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=975f7d467480a11864d71a10dee908b83c5e682b;p=pandora-kernel.git

qla2xxx: fix busy wait regression

Commit e05fe29248 (qla2xxx: Honor FCP_RSP retry delay timer field.)
causes systems to busy-wait for about 3 minutes after boot prior to
detecting SAN disks.

During this wait period one kworker is running full-time
(though /proc/<pid>/stack has no useful data). Another kworker is
waiting for IO to complete during that whole time period.

Looking at drivers/scsi/qla2xxx/qla_os.c, fcport->retry_delay_timestamp
has a special value of 0 though that 0 value forces system to wait when
jiffies is very large value (e.g. 4294952605 - "negative" value when
signed on 32bit systems).

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Acked-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

Reading git-diff-tree failed