From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: What's needed for PMP support? Date: Thu, 21 Feb 2008 10:07:40 -0500 Message-ID: <47BD93BC.3080301@pobox.com> References: <4730E312.3090900@navy.mil> <4737C16E.3070607@gmail.com> <4738827D.9060405@pobox.com> <4738F935.1000708@gmail.com> <47BC798F.6070900@pobox.com> <47BCF28F.5080702@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rune.pobox.com ([208.210.124.79]:45054 "EHLO rune.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751051AbYBUPMd (ORCPT ); Thu, 21 Feb 2008 10:12:33 -0500 In-Reply-To: <47BCF28F.5080702@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: IDE/ATA development list Tejun Heo wrote: > Hello, Mark. > > Mark Lord wrote: >> Tejun, I've added PMP to sata_mv, and am now trying to get it >> to work with a Marvell PM attached. >> >> And the behaviour I see is very bizarre. >> >> After hard+soft resets, the PM signature is found, >> and libata interrogates the PM registers. >> >> It successfully reads register 0, and then register 1. >> But all subsequent registers read out (incorrectly) as zeros. > > Hmmm... > >> I've traced the taskfiles in/out, and it all looks proper >> except for the actual data coming back from the PM. >> >> After some experimentation, I found that all of the PM registers >> were readable, if I simple inserted a sata_pmp_read(link, 0, &junk) >> in front of each issue of sata_pmp_read(link, reg, &r_val). > > Hmmmmmmm... > >> Then the PM is recognized and all, but fails port enumerations >> probably due to either my hack or the same original bug (whatever that is?) >> >> I'm confused. > > That makes two of us. > >> The PM itself works fine here on sata_sil24 and AHCI(jmicron), .. Well, last night I found someone else to try the code with a 0x1095:0x3726 (vendor/device?) Port-Multiplier. It *appears* to work fine with sata_mv, unlike the Marvell one. Hopefully the nice folks at Marvell will take a look (I've emailed them) and report back with some useful information eventually. > No but I had my fair share of problems doing PMP support for both sil24 > and ahci. Any chance you can get access to a bus analyzer? I had a > very weird problem w/ ahci PMP support which I don't think I could fix > if I didn't have access to a bus analyzer at the time. (I don't > remember details now tho.) .. I figure they must have a few of those kicking around at Marvell.. Cheers -- Mark Lord Real-Time Remedies Inc. mlord@pobox.com