From mboxrd@z Thu Jan 1 00:00:00 1970 From: gianluca Subject: pata_ali can't detect partitions Date: Mon, 9 Nov 2009 23:03:38 +0100 Message-ID: <20091109220338.GA1604@seek.priv> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="0OAP2g/MAC+5xKAE" Return-path: Received: from smtp-OUT05A.alice.it ([85.33.3.5]:2275 "EHLO smtp-OUT05A.alice.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753189AbZKIWQQ (ORCPT ); Mon, 9 Nov 2009 17:16:16 -0500 Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: linux-ide@vger.kernel.org Cc: gianluca@sottospazio.it --0OAP2g/MAC+5xKAE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hello, yesterday I tried to install archlinux-i586 on a old computer I have. It's a K6-3 with a ALI chipset. I noticed that the system was able to find the disk as sda but could not recognize the partitions on the drive. This happens with the 2.6.30-ARCH kernel of the archlinux-i586 installer. I noticed also that with an older kernel (2.6.28 IIRC) the system could detect all the partitions. So yesterday I had some spare time to try to bisect the problem with git bisect. The result of the bisection was the following commit: commit 1b2c357c301b76118973763e886d9f70a7f50f7e pata_ali: force initialise a few bits I tried to backout the commit but that didn't succeed. So I looked carefully at the diff and I came out with the attached patch which seems to fix the problem (at least now the kernel detects the partitions correctly). Since I saw that the above commit is fixing some real bugs (sunblade related) I don't know whether the attached patch is right or is backing out the intended fix. All I know is that it works for me and for this reason I'm reporting it. Thanks, Gianluca --0OAP2g/MAC+5xKAE Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="pata_ali.patch" --- linux-2.6.31/drivers/ata/pata_ali.c.orig 2009-11-08 19:01:14.000000000 +0100 +++ linux-2.6.31/drivers/ata/pata_ali.c 2009-11-09 08:30:42.000000000 +0100 @@ -453,7 +453,7 @@ /* Clear CD-ROM DMA write bit */ tmp &= 0x7F; /* Cable and UDMA */ - pci_write_config_byte(pdev, 0x4B, tmp | 0x09); + pci_write_config_byte(pdev, 0x4B, tmp | 0x08); /* * CD_ROM DMA on (0x53 bit 0). Enable this even if we want * to use PIO. 0x53 bit 1 (rev 20 only) - enable FIFO control --0OAP2g/MAC+5xKAE--