Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759806AbXEUJJi (ORCPT ); Mon, 21 May 2007 05:09:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755224AbXEUJJ3 (ORCPT ); Mon, 21 May 2007 05:09:29 -0400 Received: from nz-out-0506.google.com ([64.233.162.224]:57054 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754540AbXEUJJ2 (ORCPT ); Mon, 21 May 2007 05:09:28 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:x-enigmail-version:content-type:content-transfer-encoding; b=fA0jOCDnqUP/e7EfGLZMO9s8RWio1JPj+IKhUpZ2w4dMyOJ7M2JcP36YACXj8F7Tr+bEmlGuZZPi+oaCwwaVHz+4IGOL4daNCNpKmjxAApt1OXqpRMoocqbT+jYX7MNuB7LccELnE4RkXpsBDb8UBzESCoBjwh3VDwAdV2cjv/M= Message-ID: <465161AF.6030002@gmail.com> Date: Mon, 21 May 2007 11:09:03 +0200 From: Tejun Heo User-Agent: Thunderbird 2.0.0.0 (X11/20070326) MIME-Version: 1.0 To: Robert Hancock CC: linux-kernel , ide , l.genoni@oltrelinux.com, Alan Cox Subject: Re: something strange in libata-core.c for kernel 2.6.22-rc3 References: <46515983.6030206@shaw.ca> In-Reply-To: <46515983.6030206@shaw.ca> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1614 Lines: 33 Robert Hancock wrote: >> Alan, did you have a chance to test the ACPI cable detection? It just >> didn't work when I tried it. It always returned 80c on my machine. > > On a whim I started poking around in the disassembled ACPI DSDT code for > my Asus A8N-SLI Deluxe board, which is one of these chipsets. The > original thought was that the STM/GTM trick on these chipsets is > supposed to allow us to determine what modes we should use based on what > modes it sets up appropriately. Unfortunately, unless I'm missing > something in the AML (which is possible) it doesn't seem like there is > any validation being done on the settings passed in. The settings appear > to essentially just get programmed into the controller when STM is > called and read back on GTM. Yeah, that's consistent to what I've seen on my machine which is a variant of A8N. No matter what value I through at _STM, _GTM just echoed the result thus always leading to 80c configuration. > I guess this means that what we have to do is trust that the BIOS set up > a reasonable mode and base the cable detect on that (either by reading > back the boot-up controller registers, or by calling GTM). I imagine > this is what the Windows default IDE driver is doing (just using the > boot-up mode and feeding it back using GTM/STM on suspend/resume cycles). Alan, what do you think? -- tejun - 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/