From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: AHCI: using bios after linux Date: Fri, 12 Oct 2007 17:02:37 -0400 Message-ID: <470FE0ED.4050302@garzik.org> References: <20071012182726.37EFB4702DA@web2mail.com> <20071012215734.4b5b4bce@the-village.bc.nu> 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]:49688 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757332AbXJLVCm (ORCPT ); Fri, 12 Oct 2007 17:02:42 -0400 In-Reply-To: <20071012215734.4b5b4bce@the-village.bc.nu> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: msundius@u1.netgate.com, msundius@sundius.com, xuxiang_ins@yahoo.com, linux-ide@vger.kernel.org Alan Cox wrote: >> 3) related to #1 above, we want to be invisable. so we're not looking to >> switch from AHCI (to legacy), we are looking to continue in whatever mode >> the BIOS started in. Thus we just want BIOS to be able to handle int13 calls >> after the Linux AHCI driver has run (this works when BIOS is setup in >> legacy mode initially). > > So load the ata_piix driver and not the AHCI one and I think it'll work > out ? Sane advice under the circumstances, I suppose. Overall, its a repeat of a fundamental problem... we might be resetting the HBA, restarting the port, or any number of things that the BIOS doesn't know about. I tend to think making such calls will largely rely on luck, without some sort of in-kernel synchronization. Smart controllers do this sort of stuff, but that's a different case from the one here. Here we have competing pieces of software, each unaware of the other. Jeff