From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 06/12] sas_ata: Implement SATA PHY control Date: Tue, 06 Feb 2007 23:54:56 -0800 Message-ID: <45C985D0.7090704@gmail.com> References: <20070130091814.31530.23152.stgit@elm3a70.beaverton.ibm.com> <20070130091847.31530.6282.stgit@elm3a70.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from ug-out-1314.google.com ([66.249.92.170]:36954 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030642AbXBGRzg (ORCPT ); Wed, 7 Feb 2007 12:55:36 -0500 Received: by ug-out-1314.google.com with SMTP id 44so248871uga for ; Wed, 07 Feb 2007 09:55:36 -0800 (PST) In-Reply-To: <20070130091847.31530.6282.stgit@elm3a70.beaverton.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Darrick J. Wong" Cc: linux-scsi@vger.kernel.org, alexisb@us.ibm.com Darrick J. Wong wrote: > This patch requires "libsas: Add a sysfs knob to enable/disable a phy" > to be applied. It hooks the SControl write function to provide basic > SATA phy control for phy enable/disable and speed limits. Power > management is still broken, though it is unclear that libata actually > uses those SControl bits anyway. I don't really think exporting SControl as-is a good idea. Not all devices would act as expected if you change speed limit in SControl on the fly. Also, SATA phy speed is managed by libata core layer and used during EH. Please take a look at sata_down_spd_limit() and its usage. -- tejun