From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Warner Subject: Re: [t13] RE: comment on T10 ATA-passthru Date: Fri, 29 Oct 2004 15:39:53 -0500 Sender: linux-ide-owner@vger.kernel.org Message-ID: <20041029153953.B29944@florence.linkmargin.com> References: <20041029142539.A29944@florence.linkmargin.com> <20041029194311.GA27218@havoc.gtf.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from ms-smtp-02.rdc-kc.rr.com ([24.94.166.122]:408 "EHLO ms-smtp-02.rdc-kc.rr.com") by vger.kernel.org with ESMTP id S263522AbUJ2Ulm (ORCPT ); Fri, 29 Oct 2004 16:41:42 -0400 Content-Disposition: inline In-Reply-To: <20041029194311.GA27218@havoc.gtf.org>; from jgarzik@pobox.com on Fri, Oct 29, 2004 at 03:43:11PM -0400 List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: linville@redhat.com, linux-ide@vger.kernel.org Jeff Garzik wrote: > BTW, can you send me a patch that filters out > SET FEATURES - XFER MODE ? > > That should not be executed without driver intervention / > synchronization. There are _so_ many commands that can be terminal for continued communication with the drive, do we really want to start filtering commands ? I don't really have a dog in this fight; my personal end goal is for a drive-test-vehicle, so I'll need to be able to circumvent any blacklist anyway. I'll happily add a blacklist, but I'll just as happily add a way around it. Would it be important/useful to make the pass-thru stuff a config option ? Plus, rev 5 of the spec is out now, and rev 6 may be along soon. We're currently at rev 3 - I'll be wanting to play catch-up soon. The changes are pretty intrusive, so heads-up to anyone using it. > P.S. Any news on hotplug? Err. It's got pushed down on my task stack, I have to pop at least two things off that stack before I can get back to it. However, in working through recovery scenarios for aborted PIO/DMA transfers, it looks like I need to reset the port, which will interact with hotplug because I lose drive phy status when I issue reset via the SATA control regs. Hotplug looks like it is going to be non-trivial, even though it's not horribly complicated. My plan is to continue down the route of seperating HBA init and drive probe. For adapters that support hotplug (shouldn't all SATA ?), I plan to just let the hotplug code take care of drive probing. For HBAs that are brain dead somehow (perhaps a PATA port ?), I plan to provide some easy hook that the hba driver can call during xxx_add_one()[or whatever.] Issues already identified include flagging a drive that's absent, and failing any subsequent requests, so that we don't hang trying to sync a disk that's not there any more. Thoughts and advice wrt possible use of outboard SATA switches and how that will need to interact with hotplug would be gratefully received. Post-hotplug, I'm going to be looking at NCQ, care to share any high-level design decisions that you (or others) have already taken in that area ? -- andyw@pobox.com Andy Warner Voice: (612) 801-8549 Fax: (208) 575-5634