From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id CC68CDDDF6 for ; Thu, 22 Jan 2009 16:16:20 +1100 (EST) Subject: Re: 2.6.29-rc powerpc G5 Xorg legacy_mem regression From: Benjamin Herrenschmidt To: Hugh Dickins In-Reply-To: References: Content-Type: text/plain Date: Thu, 22 Jan 2009 16:16:10 +1100 Message-Id: <1232601370.23611.98.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, "Rafael J. Wysocki" , Jesse Barnes , linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > That's as far as I took it: I can see there's code to set up > "Legacy VGA memory" but it looks like that's not coming into play. > dmesg and .config attached: I think you'll get to the point much > quicker than I would. > > Though I bet you're busy at the moment: no hurry, I can comment > out the pci_create_legacy_files() from drivers/pci/bus.c for now. It's actually an X bug :-( IE, I always create the legacy files, I just make mmap fail when legacy VGA isn't available. This is the right way to do it, as it properly informs X that yes, I do support the new API and no, there's no point in trying to access legacy VGA memory on this machine. I honestly don't see how I can fix that without making proper support for legacy memory / IO impossible, and thus guaranteeing that X will eternally continue to crap on random bits of /dev/mem in the future :-( Cheers, Ben.