From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: AHCI support Port Multiplier problem. Date: Fri, 7 Jan 2011 16:25:37 -0500 Message-ID: <20110107212537.GH7355@mtj.dyndns.org> References: <134052.7990.qm@web74212.mail.tp2.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-vw0-f46.google.com ([209.85.212.46]:40027 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751176Ab1AGVZl (ORCPT ); Fri, 7 Jan 2011 16:25:41 -0500 Received: by vws16 with SMTP id 16so7290082vws.19 for ; Fri, 07 Jan 2011 13:25:41 -0800 (PST) Content-Disposition: inline In-Reply-To: <134052.7990.qm@web74212.mail.tp2.yahoo.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Luo Dislo Cc: jgarzik@pobox.com, linux-ide@vger.kernel.org Hello, On Fri, Jan 07, 2011 at 10:55:14AM +0800, Luo Dislo wrote: > I am using AHCI driver, when CONFIG_SATA_PMP is set and the ahci > driver DOES NOT have AHCI_HFLAG_NO_PMP. Libata sends Software Reset > with PMP=0xF, trying to detect if Port Multiplier connected to the > port. Unfortunately, if I plugged in general Hard drive, my > controller failed to identify the hard drive. > > What I observed was that libata always sent Software Reset with > PMP=0xF and I guessed expecting signature is 0x96690101. I think > libata should give up if the device does not return the Port > Multiplier signature at the first time and take the signature value > from device as the real device connnecting to the port now. > > What we said "support" PMP does not mean the port can only connnect > to Port Multiplier. It might connect with hard drive or ATAPI > device. Which controller is this? Can you please post the output of "lspci -nn"? SB600 had this problem and needed workaround but later SBs fixed it. Looks like someone else screwed up similarly. Thanks. -- tejun