From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: sata_mv port lockup on hotplug (kernel 2.6.38.2) Date: Tue, 26 Apr 2011 14:27:30 -0400 Message-ID: <4DB70E92.2020209@teksavvy.com> References: <4D9CD275.9000002@teksavvy.com> <4D9FACC9.7020200@teksavvy.com> <4DA45CA7.9040102@teksavvy.com> <4DA467FB.6020905@teksavvy.com> <20110423005610.GC1576@mtj.dyndns.org> <20110425113036.GL17734@mtj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from ironport2-out.teksavvy.com ([206.248.154.183]:47996 "EHLO ironport2-out.pppoe.ca" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751047Ab1DZS1h (ORCPT ); Tue, 26 Apr 2011 14:27:37 -0400 In-Reply-To: <20110425113036.GL17734@mtj.dyndns.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Bruce Stenning , "linux-kernel@vger.kernel.org" , "linux-ide@vger.kernel.org" On 11-04-25 07:30 AM, Tejun Heo wrote: > On Mon, Apr 25, 2011 at 12:07:04PM +0100, Bruce Stenning wrote: >> Tejun, what does it mean to limit a sata link to UDMA/100? I thought that this >> was only for ata devices, and sata devices have the choice of 1.5Gbps, 3Gbps, >> or 6 Gbps. Is that a false assumption? Is it related to early sata devices that >> were still somewhat based on parallel ata designs? > > Yeap, devices behind SATA-PATA bridge were still affected by the > transfer mode so libata tries to slow them down too along with link > speed when limiting speed due to errors. Shouldn't affect native SATA > devices. Yeah, what he said. :) First generation SATA devices were merely PATA transports with a SATA-to-PATA converter chip onboard. Some of those require that we set the transfer modes. Ditto for various more modern setups, where CF-cards, PATA drives, and other weirdos are connected through a discrete SATA bridge device. Cheers