From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: sata_via: write errors on SATA drive connected to VT6421 Date: Tue, 03 Feb 2009 10:59:10 -0500 Message-ID: <498869CE.6030902@pobox.com> References: <20090203133008.GN19493@dawn.rhaalovely.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:39674 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752322AbZBCP7Q (ORCPT ); Tue, 3 Feb 2009 10:59:16 -0500 In-Reply-To: <20090203133008.GN19493@dawn.rhaalovely.net> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Landry Breuil Cc: linux-ide@vger.kernel.org Landry Breuil wrote: > Hi, > > i encounter a very similar problem as reported in > http://marc.info/?l=linux-kernel&m=118764381013943&w=2, but with a SATA > disk. Trying to transfer 250Gb (mostly small files) from a SATA disk > (ata1/sda) to another (ata2/sdb), both plugged on the VT6421 card, after > some dozens of seconds the controler bails out and degrades write performance > (UDMA133->UDMA100->UDMA33...) > > kernel: ata2.00: limiting speed to UDMA/33:PIO4 > kernel: ata2.00: exception Emask 0x12 SAct 0x0 SErr 0x1400500 action 0x2 frozen > kernel: ata2: SError: { UnrecovData Proto Handshk TrStaTrns } > kernel: ata2.00: cmd 35/00:00:07:c6:f4/00:04:07:00:00/e0 tag 0 dma 524288 out > kernel: res 40/00:b0:27:1d:dc/84:00:07:00:00/e0 Emask 0x16 (ATA bus error) Like Robert noted, this is the hardware complaining that it has found a hardware error. "SErr" stands for SATA SError register value. That is a value read directly from hardware, which indicates one or more problems. Here is some more info: http://ata.wiki.kernel.org/index.php/Libata_error_messages#SATA_SError_expansion When libata sees a bunch of hardware problems, it tries the only things it can do to attempt progress in that situation: reset the hardware, and slow down data transfer in an attempt to avoid errors again. Jeff