Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767659AbXEDD7P (ORCPT ); Thu, 3 May 2007 23:59:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767563AbXEDD7P (ORCPT ); Thu, 3 May 2007 23:59:15 -0400 Received: from keil-draco.com ([216.193.185.50]:50139 "EHLO mail" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1767659AbXEDD7O (ORCPT ); Thu, 3 May 2007 23:59:14 -0400 From: Daniel Hazelton To: "H. Peter Anvin" Subject: Re: console font limits Date: Thu, 3 May 2007 23:58:55 -0400 User-Agent: KMail/1.9.6 Cc: Kyle Moffett , Jan Engelhardt , Geert Uytterhoeven , Albert Cahalan , "Antonino A. Daplas" , linux-kernel , aeb@cwi.nl References: <787b0d920704302109r352e6653wc71a0638cbfbdcce@mail.gmail.com> <463A80A9.7030809@zytor.com> In-Reply-To: <463A80A9.7030809@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200705032358.56055.dhazelton@enter.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2032 Lines: 36 On Thursday 03 May 2007 20:39:05 H. Peter Anvin wrote: > Kyle Moffett wrote: > > Actually I think the real problem was that "KD_GRAPHICS" got overloaded > > to mean "some userspace program is probably poking at the GPU in very > > direct ways possibly including /dev/mem". As such it really isn't safe > > at all for the kernel to write stuff to the screen in that situation; > > you could turn a panic()+reboot-after-30-secs into an unrecoverable hard > > PCI bus lockup. IIRC there were at least a couple chipsets which had > > that problem with X. If we can implement enough APIs for X to do all of > > its stuff from userspace without iopl() or /dev/mem then we could > > probably bring back the option for dumping oopses to screen in > > KD_GRAPHICS mode, but otherwise it'll just cause more headaches. > > It never meant anything *BUT* that, to the best of my knowledge. That > was certainly the original meaning of KD_GRAPHICS. I started work last year on making the framebuffer layer use the DRM internals for all controls, providing a unified kernel and userspace system for accessing the graphics devices. It never got anywhere because I couldn't figure out a simple system for figuring out which driver (out of the numerous ones that could potentially be compiled into the kernel) to actually give control to. (I know I could have just looped over them all and figured it out that way, but that is far from elegant) I guess I could start on that work again - shouldn't take me all that long to recover the stuff I lost when a blackout caused my hard drive to get corrupted beyond recovery (and the automated journal replay didn't do a damned thing - I think it actually *added* to the corruption, but I don't think any filesystem would have survived that) DRH - 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/