From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCHSET] libata: new reset mechanism, take#2 Date: Tue, 24 Jan 2006 17:05:21 +0900 Message-ID: <1138089921565-git-send-email-htejun@gmail.com> Reply-To: Tejun Heo Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from xproxy.gmail.com ([66.249.82.196]:6342 "EHLO xproxy.gmail.com") by vger.kernel.org with ESMTP id S1030352AbWAXIF3 (ORCPT ); Tue, 24 Jan 2006 03:05:29 -0500 Received: by xproxy.gmail.com with SMTP id s14so770397wxc for ; Tue, 24 Jan 2006 00:05:26 -0800 (PST) In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: jgarzik@pobox.com, linux-ide@vger.kernel.org, albertcc@tw.ibm.com Cc: htejun@gmail.com Hello, all. This is the second take of new reset mechanism patchset and against upstream-2.6.17 + eh-misc-updates patchset + three ahci update patches I've sent yesterday. The goals of new reset mechanism are. * Do not allow individual reset methods manipulate libata internal data structures (e.g. disable port) to give more control to higher driving logic (e.g. to allow retries). * Goes hand-in-hand with above. Make low level operations easily shareable with other uses (probe and EH). * Minimize code duplications but yet allow flexibility if needed. Major difference from the first take is that core layer doesn't directly drive resets anymore. It just calls ->probe_reset and the rest is upto the low level driver. However, as reset driving logic is identical for most drivers, helper routines are supplied such that low level drivers only have to implement supported reset operations. Jeff, I think the above change hopefully resolves your concern about fixed driving logic. The other issue was regarding how reset itself should be performed - resets are event-driven in nature and should be implemented accordingly as a qc protocol. I still disagree and don't really see how it can be done. My rationales are in the following two messages. Can you please share your thoughts in deeper detail? http://marc.theaimsgroup.com/?l=linux-ide&m=113497224219265&w=2 http://marc.theaimsgroup.com/?l=linux-ide&m=113497644716191&w=2 Thanks. -- tejun