Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261433AbVBVTTj (ORCPT ); Tue, 22 Feb 2005 14:19:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261426AbVBVTTj (ORCPT ); Tue, 22 Feb 2005 14:19:39 -0500 Received: from fire.osdl.org ([65.172.181.4]:35979 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S261326AbVBVTTT (ORCPT ); Tue, 22 Feb 2005 14:19:19 -0500 Date: Tue, 22 Feb 2005 11:19:10 -0800 (PST) From: Linus Torvalds To: Jon Smirl cc: Benjamin Herrenschmidt , Dave Airlie , dri-devel@lists.sourceforge.net, xorg@lists.freedesktop.org, Linux Kernel list Subject: Re: POSTing of video cards (WAS: Solo Xgl..) In-Reply-To: <9e473391050221204215a079e1@mail.gmail.com> Message-ID: References: <4218BAF0.3010603@tungstengraphics.com> <21d7e997050220150030ea5a68@mail.gmail.com> <9e4733910502201542afb35f7@mail.gmail.com> <1108973275.5326.8.camel@gaston> <9e47339105022111082b2023c2@mail.gmail.com> <1109019855.5327.28.camel@gaston> <9e4733910502211717116a4df3@mail.gmail.com> <1109041968.5412.63.camel@gaston> <9e473391050221204215a079e1@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1940 Lines: 43 On Mon, 21 Feb 2005, Jon Smirl wrote: > > I was working on the assumption that all PCI based, VGA class hardware > that is not the boot device needs to be posted. I don't think that's true. We certainly don't _want_ it to be true in the long run - and even now there are cards that we can initialize fully without using the BIOS at all. > And that the posting should occur before the drivers are > loaded. Personally, I'd much rather let the driver be involved in the decision. That may mean that the probe routine knows how to initialize the card, but it may mean that it does an "exec_usermodehelper()" kind of thing. Actually, I'd prefer it if this was largely up to "udev": if the driver notices that it can't initialize the card, why not just enumerate it enough that "udev" knows about it (that's pretty much automatic), and let the driver just ignore the card until some (possibly much later) date when the user level scripts have found it and initialized it. That would imply that the driver have some "re-attach" entrypoint (which migth be a ioctl, but might also be just a /sysfs file access), which is the user-lands way of saying "try again - I've now initialized the hardware". The advantage of that kind of "disconnected" initialization is that you don't _need_ to have the card initialization in initramfs or other "very early boot" sequence. It gets _detected_ early on, but you can then delay initializing it arbitrarily long, and it obviously won't be usable until that point (but who cares? The ones that do care can put the things in their initramfs, others may decide to do it only once the system is up-and-running and /usr has been NFS-mounted). Linus - 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/