From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH] libata: Use IGN_SIMPLEX for ALi Date: Wed, 13 May 2009 16:15:37 +0200 Message-ID: <200905131615.38013.bzolnier@gmail.com> References: <20090513135855.11205.36917.stgit@t61.ukuu.org.uk> <200905131532.38811.bzolnier@gmail.com> <20090513144904.1fd2cca9@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from an-out-0708.google.com ([209.85.132.245]:16050 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032AbZEMOLr (ORCPT ); Wed, 13 May 2009 10:11:47 -0400 Received: by an-out-0708.google.com with SMTP id d40so1032257and.1 for ; Wed, 13 May 2009 07:11:48 -0700 (PDT) In-Reply-To: <20090513144904.1fd2cca9@lxorguk.ukuu.org.uk> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: jeff@garzik.org, linux-ide@vger.kernel.org On Wednesday 13 May 2009 15:49:04 Alan Cox wrote: > > [ Sigh, this issue seems to go back to: > > > > commit 669a5db411d85a14f86cd92bc16bf7ab5b8aa235 > > Author: Jeff Garzik > > Date: Tue Aug 29 18:12:40 2006 -0400 > > > > [libata] Add a bunch of PATA drivers. ] > > No its quite recent actually - broke around 2.6.27 > > The libata drivers try and reset the simplex bits to check if a device is > merely in simplex mode by configuration. Unfortunately on the ALi if you > put the device into a power saving mode and bring it back the simplex > bits get corrupted and the register becomes unwritable (even to restore) > > Somewhere around 2.6.27 something started rudely dumping the device into > power saving mode outside of the ATA layer on certain PCs. > > So we switch to ignoring the bit in the first place on this chip. Ok, thanks for explaining it. BTW you may consider removing ata_pci_bmdma_clear_simplex() call from ali_init_chipset() now (before somebody decides to fix the code to check the former's function return value).