From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Sealey Subject: Re: how to handle pata_via when controller not in fully-pci-native mode (two irqs?) Date: Wed, 04 Jul 2007 20:08:03 +0100 Message-ID: <468BF013.7030601@genesi-usa.com> References: <467C689E.3050800@genesi-usa.com> <20070623103349.23cad9b7@the-village.bc.nu> <467CE8FA.2040304@genesi-usa.com> <20070623105344.3ece6db1@the-village.bc.nu> <467CF1E6.8000905@genesi-usa.com> <4689FBCB.90608@gmail.com> <468A04A0.1020003@genesi-usa.com> <20070703131736.5ddc0b89@the-village.bc.nu> <468A41CC.6030203@genesi-usa.com> <20070703143809.5064fa35@the-village.bc.nu> <468A5223.4050906@genesi-usa.com> <20070703145334.2bc9b773@the-village.bc.nu> <468A5532.9020600@genesi-usa.com> <468B608B.50803@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mithrandir.softwarenexus.net ([66.98.186.96]:2441 "EHLO mail.genesi-usa.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756389AbXGDTHW (ORCPT ); Wed, 4 Jul 2007 15:07:22 -0400 In-Reply-To: <468B608B.50803@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Alan Cox , linux-ide@vger.kernel.org Tejun Heo wrote: > > I forgot about the PCI resource fix up done for legacy hosts. I think > making the host legacy is the best way to take here considering that - > no change for both ide and libata, just some fix up in platform code. > ATA native/legacy thing doesn't mean much. It's just how the resources > are allocated. Is there any specific reason to use native mode? Yes, legacy mode means there are several "io ports" mapped into the 0 thru 0x1000 addresses. This might work in Linux, granted, but I am not sure it is a good idea in the first place. Mapping io ports to anywhere but the PCI io space is just an ugly solution. The ATA native/legacy thing means a lot, as there is no "legacy" on PowerPC. It's a PCI device, so we should try and fix up it's actions as a PCI device, however, making it truly conform will break any "not entirely compatible" drivers break (via8cxxx being the biggest culprit). Therefore no firmware fixes for thee. I do think we can knock it into full PCI native mode from the platform fixups though, as a kernel option. Old drivers will work fine, old kernels will work fine, and optionally old behaviour can be left, but anyone building a new kernel with pata_via and no via8cxxx (i.e. all new distributions) can enable the new behaviour. Does that sound okay? No libata-level resource fixups need to be done for a real PCI device, do they? I think we should just coerce the controller to use a single interrupt and disable ISA interrupt steering, fix the class code, and see if libata handles it. -- Matt Sealey Genesi, Manager, Developer Relations