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 10:57:32 +0900 Message-ID: <47BE2C0C.3020801@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> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from wx-out-0506.google.com ([66.249.82.233]:56854 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751869AbYBVB5l (ORCPT ); Thu, 21 Feb 2008 20:57:41 -0500 Received: by wx-out-0506.google.com with SMTP id h31so225257wxd.4 for ; Thu, 21 Feb 2008 17:57:38 -0800 (PST) In-Reply-To: <47BE1833.9090501@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: > Mark Lord wrote: >> Tejun Heo wrote: >>>> >>>> The following things are needed for a LLD to support PMP. >>> .. >>>> I think that's about it. Feel free to ask if something isn't clear. >> .. >> >> I think we need better semantics around sata_scr_{read,write}(), >> or more specifically >> These need to be moved into ata_port_operations >> so that LLDs can wrap them to properly manage >> the host controller's global link->pmp value. > .. > > Heck, if .dev_select() took a *device* instead of a *port* > as it's parameter, then I could probably manage it fine in there. 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. Thanks. -- tejun