From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Adding port multiplier support to a LLDD Date: Mon, 23 Jun 2008 09:22:24 +0900 Message-ID: <485EECC0.40902@kernel.org> References: <5d74c5720806211335i12cd4764j2109703ab224b1cb@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:37495 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751531AbYFWAWe (ORCPT ); Sun, 22 Jun 2008 20:22:34 -0400 In-Reply-To: <5d74c5720806211335i12cd4764j2109703ab224b1cb@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mark Miesfeld Cc: linux-ide@vger.kernel.org Mark Miesfeld wrote: > Hi, > > I wonder if someone could give me a broad outline of what is needed to > add port multiplier support to a low-level SATA device driver through > libata in a 2.6.26 kernel. > > I'm working on a driver for a new SOC (460EX) that AMCC has. The chip > has support for SATA and support for port multipliers through > command-based switching. > > For our in-house validation boards I have the driver working on a > 2.6.19 kernel and implemented the port multiplier support within the > driver itself since libata didn't yet have port multiplier support. > > Our customer evaluation boards (Canyonlands) are using a 2.6.26 > kernel. Stefan Roese at DENX has ported the 2.6.19 driver to 2.6.26 > but without port multiplier support. In 2.6.26 the libata port > multiplier support looks pretty good, I was hoping I can add the > support to the 2.6.26 driver fairly easily by going through libata. > > What basic steps should I take? The following thread should help. http://thread.gmane.org/gmane.linux.ide/24799 -- tejun