From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 12/15] libata: use SATA speeding down in ata_drive_probe_reset() Date: Sun, 02 Apr 2006 10:05:48 +0900 Message-ID: <442F236C.9030908@gmail.com> References: <11438230992911-git-send-email-htejun@gmail.com> <442EDAD9.9040308@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from zproxy.gmail.com ([64.233.162.192]:10347 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S932360AbWDBBF4 (ORCPT ); Sat, 1 Apr 2006 20:05:56 -0500 Received: by zproxy.gmail.com with SMTP id o37so1361564nzf for ; Sat, 01 Apr 2006 17:05:55 -0800 (PST) In-Reply-To: <442EDAD9.9040308@pobox.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: alan@lxorguk.ukuu.org.uk, albertcc@tw.ibm.com, linux-ide@vger.kernel.org, "Eric D. Mudama" Jeff Garzik wrote: > Tejun Heo wrote: >> Make ata_drive_probe_reset() use SATA SPD configuration. Hardreset >> will be force if speed renegotiation is necessary. Also, if a >> hardreset fails, PHY speed is stepped down and hardreset is retried >> until the lowest speed is reached. >> >> Signed-off-by: Tejun Heo > > Tentative ACK: I wonder if a naked COMRESET is the best procedure for > changing PHY speeds. We might even power down the phy, change speeds, > and then power it up again. Need to reach my SATA docs, and maybe talk > to some device/controller vendors. > AFAICS, SATA doc doesn't say anything about how to change PHY speed. FYI, ICH7 AHCI works fine with the current implementation. I'm a bit skeptical about doing naked COMRESET from libata core layer. I think the right direction is to make SATA spd configuration the responsibility of hardreset operation. -- tejun