From: Chip Coldwell <coldwell@redhat.com>
Subject: [RHEL-5.1 PATCH] 3/4: fix for slow DVD drive
Date: Mon, 4 Jun 2007 11:58:04 -0400 (EDT)
Bugzilla: 240910
Message-Id: <Pine.LNX.4.64.0706041154470.19914@bogart.boston.redhat.com>
Changelog: [scsi] fix for slow DVD drive


bz240910

    Doug Chapman writes:
    
    Upstream testing has found a regression in the LSI mptspi driver
    which causes extremely slow DVD drive performance (on the order of
    150x slower) on some of the high-end HP Integrity servers.  This
    issue for the upstream kernels has been reported at:
    
    http://bugzilla.kernel.org/show_bug.cgi?id=8426
    
    We will need this fix included when the new LSI mptspi driver is
    included in RHEL as per bug #225177
    
    I have provided a patch upstream for this however it has not yet
     been accepted.  Either this or another fix for this issue will be
     required.  My patch can be found at:
    
    http://www.mail-archive.com/linux-scsi@vger.kernel.org/msg06937.html
    
    This patch has been accepted by Eric Moore of LSI, so it will go upstream.

diff --git a/drivers/message/fusion/mptspi.c b/drivers/message/fusion/mptspi.c
index a3a6acb..545345a 100644
--- a/drivers/message/fusion/mptspi.c
+++ b/drivers/message/fusion/mptspi.c
@@ -726,13 +726,15 @@ static int mptspi_slave_configure(struct scsi_device *sdev)
 	struct _MPT_SCSI_HOST *hd =
 		(struct _MPT_SCSI_HOST *)sdev->host->hostdata;
 	VirtTarget *vtarget = scsi_target(sdev)->hostdata;
-	int ret = mptscsih_slave_configure(sdev);
+	int ret;
+
+	mptspi_initTarget(hd, vtarget, sdev);
+
+	ret = mptscsih_slave_configure(sdev);
 
 	if (ret)
 		return ret;
 
-	mptspi_initTarget(hd, vtarget, sdev);
-
 	ddvprintk((MYIOC_s_INFO_FMT "id=%d min_period=0x%02x"
 		" max_offset=0x%02x max_width=%d\n", hd->ioc->name,
 		sdev->id, spi_min_period(scsi_target(sdev)),


-- 
Charles M. "Chip" Coldwell
Senior Software Engineer
Red Hat, Inc
978-392-2426