From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: What's needed for PMP support? Date: Fri, 22 Feb 2008 11:12:46 +0900 Message-ID: <47BE2F9E.5040206@gmail.com> References: <4730E312.3090900@navy.mil> <4737C16E.3070607@gmail.com> <4738827D.9060405@pobox.com> <4738F935.1000708@gmail.com> <47BC798F.6070900@pobox.com> <47BE17CA.6060406@rtr.ca> <47BE1833.9090501@rtr.ca> <47BE2C0C.3020801@gmail.com> <47BE2DBD.9010704@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from wr-out-0506.google.com ([64.233.184.235]:56901 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753439AbYBVCMy (ORCPT ); Thu, 21 Feb 2008 21:12:54 -0500 Received: by wr-out-0506.google.com with SMTP id c48so389145wra.23 for ; Thu, 21 Feb 2008 18:12:52 -0800 (PST) In-Reply-To: <47BE2DBD.9010704@rtr.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mark Lord Cc: IDE/ATA development list , Saeed Bishara Mark Lord wrote: >> Heh... I never thought a PMP aware controller would use TF SRST, so what >> you want to do is set pmp value in the register and calling >> ata_std_softreset(), right? I think the correct thing to do is to >> separate out SRST sequence proper from ata_std_softreset() into, say, >> ata_sff_SRST() and build custom softreset around it. After all, the >> problem here is the reset sequence not the SCR access. > .. > > Actually, I believe the problem *is* the (pmp) SCR access. > The same issue will return again when trying to support hotplug, for > example. Can you elaborate a bit? > Any SCR access will steal the active pmp on such hosts. > > I think we really do need to snoop those, somehow. Adding ->sata_pmp_scr_read/write should do but I wanna avoid that if possible. Thanks. -- tejun