From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH] mvsas: defer non-NCQ cmds when NCQ cmds are active Date: Tue, 21 Sep 2010 15:51:14 -0500 Message-ID: <1285102274.16440.132.camel@mulgrave.site> References: <20100921191701.GA16726@dhcp-10-15-1-70.hsv.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from cantor.suse.de ([195.135.220.2]:45067 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755609Ab0IUUvT (ORCPT ); Tue, 21 Sep 2010 16:51:19 -0400 In-Reply-To: <20100921191701.GA16726@dhcp-10-15-1-70.hsv.redhat.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: David Milburn Cc: linux-scsi@vger.kernel.org, jeff@garzik.org, k.skarlatos@gmail.com On Tue, 2010-09-21 at 14:17 -0500, David Milburn wrote: > Non-NCQ commands should run exclusively, ata_qc_issue warns when mixing > non-NCQ and NCQ commands. > > Signed-off-by: David Milburn > Reported-by: Konstantinos Skarlatos > --- > drivers/scsi/libsas/sas_ata.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c > index 042153c..ddbade7 100644 > --- a/drivers/scsi/libsas/sas_ata.c > +++ b/drivers/scsi/libsas/sas_ata.c > @@ -347,6 +347,7 @@ static int sas_ata_scr_read(struct ata_link *link, unsigned int sc_reg_in, > static struct ata_port_operations sas_sata_ops = { > .phy_reset = sas_ata_phy_reset, > .post_internal_cmd = sas_ata_post_internal, > + .qc_defer = ata_std_qc_defer, What does this do on the card that doesn't need it: the aic94xx? That one takes in a pipeline of commands and takes responsibility for getting the issue right. Something like this throttles the pipeline higher than the aic94xx is expecting. However, as long as it's not too much of a performance problem, I don't mind applying it. James