From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: sata_via (pata): problems when write cache is disabled Date: Mon, 30 Apr 2007 11:52:02 +0200 Message-ID: <4635BC42.6020201@gmail.com> References: <20070429105001.GA4530@deprecation.cyrius.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0506.google.com ([64.233.162.234]:6541 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030939AbXD3TuX (ORCPT ); Mon, 30 Apr 2007 15:50:23 -0400 Received: by nz-out-0506.google.com with SMTP id o1so2031854nzf for ; Mon, 30 Apr 2007 12:50:22 -0700 (PDT) In-Reply-To: <20070429105001.GA4530@deprecation.cyrius.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Martin Michlmayr Cc: linux-ide@vger.kernel.org, "Williams, Dan J" Martin Michlmayr wrote: > Is this a bug in the VIA driver? > > Sample errors: > > ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 > ata3.00: (BMDMA stat 0x4) > ata3.00: cmd ca/00:08:08:80:04/00:00:00:00:00/e0 tag 0 cdb 0x0 data 4096 out > res 53/84:00:0f:80:04/00:00:00:00:00/e0 Emask 0x10 (ATA bus error) I doubt it's the driver's fault. It's more likely actual wiring problem. In the first two dmesgs, even UDMA/25 doesn't work. Errors stop only after it drops speed down to PIO4. The only thing driver can do to cause this PATA transmission errors I can think of is misprogramming the timing registers but transfer mode programming on vt6421 is as simple as telling the controller the index of the mode, so it's pretty hard to screw up there. The difference between the first two and the last one might be that the last one is just more tolerant about degraded signals. (e.g. some of latest PATA drives can do UDMA/100 on 40c cable w/o any problem). -- tejun