From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Falk Subject: Re: libata SATA support for Sil 3726 port multiplier Date: Tue, 18 Jul 2006 17:21:02 -0700 Message-ID: <44BD7AEE.8020805@google.com> References: <44B3D0B6.7070506@coplanar.net> <44BD72BD.70105@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp-out.google.com ([216.239.33.17]:25761 "EHLO smtp-out.google.com") by vger.kernel.org with ESMTP id S932230AbWGSAWa (ORCPT ); Tue, 18 Jul 2006 20:22:30 -0400 In-Reply-To: <44BD72BD.70105@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Fredrik Sjoholm , Jeremy Jackson , Jeff Garzik , linux-ide@vger.kernel.org > Yes, we have yet to implement staggered spinup support with someway to > control the number of concurrently spun up devices. It's on my agenda. > SATA staggered spinup is enabled by loading certain pin in the power > connector during power-up. So, it is the enclosure which determines > whether staggered spin-up is enabled or disabled. Your enclosure may > have a dip switch or something to control that. Doing staggered spinup properly is a tricky thing -- the sequence that spins up the drive is the same sequence that detects the drive. This means that simply probing the controller for disk drives will spin them up. So staggered spinup means staggered probling. Tricky. -ed falk