From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IJZ1u-00065r-Ew for qemu-devel@nongnu.org; Fri, 10 Aug 2007 14:16:10 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IJZ1s-00065C-UB for qemu-devel@nongnu.org; Fri, 10 Aug 2007 14:16:10 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IJZ1s-000658-P1 for qemu-devel@nongnu.org; Fri, 10 Aug 2007 14:16:08 -0400 Received: from mail.codesourcery.com ([65.74.133.4]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1IJZ1s-0003g5-9o for qemu-devel@nongnu.org; Fri, 10 Aug 2007 14:16:08 -0400 From: Paul Brook Subject: Re: [Qemu-devel] [PATCH/RFC] Set a (distinguishable) subsystem id for Cirrus VGA Date: Fri, 10 Aug 2007 19:16:02 +0100 References: <1186687670.26986.19.camel@erebor.boston.redhat.com> <200708101728.30489.paul@codesourcery.com> <1186766002.11930.22.camel@localhost.localdomain> In-Reply-To: <1186766002.11930.22.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200708101916.02932.paul@codesourcery.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Jeremy Katz On Friday 10 August 2007, Jeremy Katz wrote: > On Fri, 2007-08-10 at 17:28 +0100, Paul Brook wrote: > > On Thursday 09 August 2007, Jeremy Katz wrote: > > > The attached adds a PCI subsystem vendor ID of 0x514D (QM ascii->hex) > > > for the Cirrus emulation so that you can tell that the system is > > > running under qemu. This will make it so that, eg, we can detect that > > > in X and know that resolutions > 800x600 won't blow up a monitor. > > > > I'd rather not. If you want autodetection to work then implement vesa DDC > > emulation. > > The Cirrus hardware never supported it, so it's basically going to be > making up all new code for the emulation, the drivers, etc. My sources say otherwise. The current Xorg cirrus driver clearly has DDC (aka i2c) support, and there's a patch for linux framebuffer support here: http://lkml.org/lkml/2006/7/4/230 qemu already have a generic i2c framework, and i2c EEPROM devices (used to hold the EDID), so all you need to implement is the cirrus host bits. It's not entirely trivial as the card sees to just expose the raw signal lines. However i2c is fairly straightforward, so it shouldn't be that hard to implement. Paul