Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 28 Jul 2002 19:34:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 28 Jul 2002 19:34:36 -0400 Received: from mallaury.noc.nerim.net ([62.4.17.82]:16397 "HELO mallaury.noc.nerim.net") by vger.kernel.org with SMTP id ; Sun, 28 Jul 2002 19:34:35 -0400 Message-ID: <3D448052.4070805@inet6.fr> Date: Mon, 29 Jul 2002 01:37:54 +0200 From: Lionel Bouton User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020605 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Alan Cox , Lei-Chun Chang , Andre Hedrick , Marcelo Tosatti , linux-kernel Subject: SiS 5513 ATA133 support patch for 2.4.19-rc3-ac3 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2165 Lines: 51 Hi, Marcelo, I was mistaken when I told you that the patch (adding ATA133 support and bringing sis5513.c from v0.13 to v0.14) only brought performance enhancements. The matter is far more complicated. Background: - sis5513.c v0.13 looks only for a set of known northbridge PCI IDs instead of using a more fine probing, - SiS started to produce separate northbridge/southbridge chips. From earliest bugreports I believed updated southbridges came with new northbriges too (reports indicated "646" for 645DX and thus the driver didn't recognised the chip and fallbacked to original SiS5513 mode -> no data corruption) and didn't bother. Today I received a report for v0.13 with a *645* ID for a 645DX. This ID is recognised as only ATA100-capable -> data corruption occured (problem solved with v0.14). So I'm now sure we will have data corruption with v0.13 (we overclock the IDE UDMA writes for problematic configurations). A workaround would be to remove support for problematic PCI IDs in v0.13. *But* I guess we have an unresolvable problem in v0.13 with latest southbridges (962/963): the register layout changed completely. Unlike previous chipsets, fallback to sis5513 mode could fail. I guess that the master of the primary controller would be fine when the registers aren't relocated (may be BIOS dependant or even worse, having booted another OS dependant). But all other IDE devices could be screwed up and all of them can be if the registers have been remapped. The only workaround for this is a v0.14 with enough time for tests. Before releasing 2.4.19 I think we should either : - completely remove the affected northbridges (645, 650, 745, 750) support in v0.13, this is a simple patch. Then we wait for 2.4.20 to include v0.14. - put v0.14 in. From past experiences we need 2 weeks of availability of code in the AC/pre kernels before the wave of meaningful bugreports ends. LB. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/