From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Fwd: confusion about libata.force=80c Date: Wed, 21 May 2008 14:57:09 +0900 Message-ID: <4833B9B5.7060601@gmail.com> References: <57947bf80805141120v615ef957g323114637d171f0a@mail.gmail.com> <57947bf80805200222j19efa2d2n7ff89fe026745ba1@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from py-out-1112.google.com ([64.233.166.180]:64930 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754940AbYEUF5S (ORCPT ); Wed, 21 May 2008 01:57:18 -0400 Received: by py-out-1112.google.com with SMTP id p76so4386pyb.10 for ; Tue, 20 May 2008 22:57:15 -0700 (PDT) In-Reply-To: <57947bf80805200222j19efa2d2n7ff89fe026745ba1@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tom Sylla Cc: linux-ide@vger.kernel.org Tom Sylla wrote: > Anyone have a comment? All I am asking for now is if this *should* > work or not. Is force=80c supposed to do what I want? > > > ---------- Forwarded message ---------- > From: Tom Sylla > Date: Wed, May 14, 2008 at 2:20 PM > Subject: confusion about libata.force=80c > To: linux-ide@vger.kernel.org > > > I have a platform with a single CompactFlash socket connected to a > Broadcom HT1000's PATA port. With libata's pata_serverworks, it ends > up using drive-side 80-conductor cable detection (Broadcom provides no > cable bits for the BIOS to report what is attached). The > CompactFlashes I am using mis-report the cable type, and > pata_serverworks limits to UDMA2. I tried to use the recent addition > of libata.force, but it does not seem to work like I would expect it > to. An excerpt from dmesg: > > scsi4 : pata_serverworks > scsi5 : pata_serverworks > ata5: PATA max UDMA/66 cmd 0x1f0 ctl 0x3f6 bmdma 0xffa0 irq 14 > ata6: PATA max UDMA/66 cmd 0x170 ctl 0x376 bmdma 0xffa8 irq 15 > ata5: FORCE: cable set to 80c > ata5.00: ATA-4: CF CARD, 20080308, max UDMA/66 > ata5.00: 15662304 sectors, multi 0: LBA > ata5.00: limited to UDMA/33 due to 40-wire cable > ata5.00: configured for UDMA/33 > > The force parameter is certainly getting accepted, but then 3 lines > later, it believes it has a 40 conductor cable. > > I have attached the full dmesg. This is vanilla 2.6.25.3 with "options > libata force=80c" added in the initrd. > > Yes, I know I should just get a more well-behaved device, but both of > the high-speed (UDMA) CFs I am using mis-report the cable detection. I > would bet many other high-speed CFs do the same. I have already > contacted the CF manufacturer to look into it. For now, though, I'd > like to run UDMA4, and the force parameter seems like it would do what > I want. > > Is force=80c what I want? Should it work? It should but is overridden by device side cable detection upto 2.6.25. 2.6.26 will have it fixed. force=udma66 should work. -- tejun