Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268582AbUI2O5m (ORCPT ); Wed, 29 Sep 2004 10:57:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268637AbUI2Oyk (ORCPT ); Wed, 29 Sep 2004 10:54:40 -0400 Received: from colossus.systems.pipex.net ([62.241.160.73]:29605 "EHLO colossus.systems.pipex.net") by vger.kernel.org with ESMTP id S268502AbUI2O1R (ORCPT ); Wed, 29 Sep 2004 10:27:17 -0400 Message-ID: <415AC640.3090407@tungstengraphics.com> Date: Wed, 29 Sep 2004 15:27:12 +0100 From: Keith Whitwell User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8a3) Gecko/20040817 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Christoph Hellwig Cc: Discuss issues related to the xorg tree , dri-devel , lkml Subject: Re: New DRM driver model - gets rid of DRM() macros! References: <9e4733910409280854651581e2@mail.gmail.com> <20040929133759.A11891@infradead.org> <415AB8B4.4090408@tungstengraphics.com> <20040929143129.A12651@infradead.org> <415ABA34.9080608@tungstengraphics.com> <415AC2B3.6070900@tungstengraphics.com> <20040929151601.A13135@infradead.org> In-Reply-To: <20040929151601.A13135@infradead.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1306 Lines: 27 Christoph Hellwig wrote: > On Wed, Sep 29, 2004 at 03:12:03PM +0100, Keith Whitwell wrote: > >>Thinking about it, it may not have been a problem of crashing, but rather that >> the behaviour visible from a program attempting to read (or poll) was >>different with noop versions of these functions to NULL versions, and that was >>causing problems. This is 18 months ago, so yes, I'm being vague. >> >>The X server does look at this file descriptor, which is where the problem >>would have arisen, but only the gamma & maybe ffb drivers do anything with it. > > > Indeed, for read you're returning 0 now instead of the -EINVAL from common > code when no ->read is present. I'd say the current drm behaviour is a bug, > but if X drivers rely on it. I'd agree, but it's a widely distributed bug. I guess we can fix it in the X server, but even better would be to rip out the code as it's fundamentally misguided, based on a wierd idea that the kernel would somehow ask the X server to perform a context switch between two userspace clients... Keith - 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/