From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Hancock Subject: Re: [patch 29/30] sata_nv: don't read shadow registers when in ADMA mode Date: Fri, 09 Mar 2007 08:27:47 -0600 Message-ID: <45F16EE3.40602@shaw.ca> References: <200703061038.l26AcD3M019553@shell0.pdx.osdl.net> <45F154A8.1050606@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:13970 "EHLO pd2mo2so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767313AbXCIO1t (ORCPT ); Fri, 9 Mar 2007 09:27:49 -0500 In-reply-to: <45F154A8.1050606@garzik.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik , linux-kernel Cc: akpm@linux-foundation.org, linux-ide@vger.kernel.org Jeff Garzik wrote: > akpm@linux-foundation.org wrote: >> From: Robert Hancock >> >> Reading from the ATA shadow registers while we are in ADMA mode may cause >> undefined behavior. Don't read the ATA status register when completing >> commands for this reason, it shouldn't be needed as the controller will >> notify us if the command failed. Also, don't allow commands with result >> taskfile requested to execute in ADMA mode, since that requires accessing >> the shadow registers. We also still need to override tf_read since >> libata >> will read the result taskfile on a command failure, and we need to go >> into >> port register mode before allowing this. >> >> Signed-off-by: Robert Hancock >> Signed-off-by: Andrew Morton >> --- >> >> drivers/ata/sata_nv.c | 33 ++++++++++++++++++++------------- >> 1 file changed, 20 insertions(+), 13 deletions(-) > > Robert, do you think this should be pushed into #upstream-fixes > (2.6.21-rc)? > > I lean towards "yes", since it is a needed-by-hardware fix, but I also > am interested in testing feedback since it is so late in the 2.6.21-rc > game. I would lean toward that as well, but it would be good to get some testing from some sata_nv ADMA users to make sure it doesn't do anything funny for them.. -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/