From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262899AbVG3BnP (ORCPT ); Fri, 29 Jul 2005 21:43:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262913AbVG3BlQ (ORCPT ); Fri, 29 Jul 2005 21:41:16 -0400 Received: from wproxy.gmail.com ([64.233.184.196]:27017 "EHLO wproxy.gmail.com") by vger.kernel.org with ESMTP id S262808AbVG3BkF (ORCPT ); Fri, 29 Jul 2005 21:40:05 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:user-agent:x-accept-language:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding:from; b=I1G6rkFni4/MiTY48m/OVhcq5SmWqgmPhyZk+Bqv+iTPYa/pWQ6mxU+T3xLPw8B3FVEsRLKnG9tFt+ILc3fs1orMOXEu6+Y8wsY7Mz7Ye7pb9I+4jk/x4oxZXLXHMYzyehSDSkfku889zDHk7lyMsH+hY9BLBg7/Xj78hcTthtc= Message-ID: <42EADA76.2050606@pol.net> Date: Sat, 30 Jul 2005 09:40:06 +0800 User-Agent: Mozilla Thunderbird 1.0.6 (X11/20050715) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Morton CC: Dave Jones , linux-kernel@vger.kernel.org, adaplas@gmail.com, ak@suse.de Subject: Re: vesafb-fix-mtrr-bugs.patch added to -mm tree References: <200507291825.j6TIParH012406@shell0.pdx.osdl.net> <20050729185848.GP17003@redhat.com> <20050729180827.79679ff0.akpm@osdl.org> In-Reply-To: <20050729180827.79679ff0.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit From: "Antonino A. Daplas" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > Dave Jones wrote: >> On Fri, Jul 29, 2005 at 11:24:37AM -0700, Andrew Morton wrote: >> >> > From: "Antonino A. Daplas" >> > >> > >> vesafb: mode is 800x600x16, linelength=1600, pages=16 >> > >> vesafb: scrolling: redraw >> > >> vesafb: Truecolor: size=0:5:6:5, shift=0:11:5:0 >> > >> mtrr: type mismatch for fc000000,1000000 old: write-back new: write- >> > >> combining >> > >> > Range is already set to write-back, vesafb attempts to add a write-combining >> > mtrr (default for vesafb). >> > >> > >> mtrr: size and base must be multiples of 4 kiB >> > >> > This is a bug, vesafb attempts to add a size < PAGE_SIZE triggering >> > the messages below. >> >> I fixed this a few weeks back. It's this line which your patch removes.. >> >> - while (temp_size > PAGE_SIZE && >> >> > To eliminate the warning messages, you can add the option mtrr:2 to add a >> > write-back mtrr for vesafb. Or just use nomtrr option. >> >> If we need users to pass extra command line args to make warnings go >> away, we may as well not bother. Because 99% of users will be completely >> unaware that option even exists. They'll still see the same message, >> and still report the same bugs. >> >> The pains of MTRR strike again. This stuff is just screaming for >> a usable PAT implementation. Andi, you were working on that, any news ? >> Or should I resurrect Terrence's patch again ? >> > > Well something is still awry: > > > > > Begin forwarded message: > > Date: Fri, 29 Jul 2005 13:40:05 +0200 > From: Alessandro > To: Andrew Morton > Subject: Re: "mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining" on Kernel 2.6.12 > > > I try the new prepatch for the stable Linux kernel (2.6.13-rc4) but > the problem is the same: > ... > vesafb: framebuffer at 0xe0000000, mapped to 0xe0880000, using 4608k, > total 131072k > vesafb: mode is 1024x768x24, linelength=3072, pages=55 > vesafb: protected mode interface info at c000:56cb > vesafb: scrolling: redraw > vesafb: Truecolor: size=0:8:8:8, shift=0:16:8:0 > mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,4000000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,2000000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,1000000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,800000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,400000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,200000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,100000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,80000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,40000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,20000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,10000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,8000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,4000 old: write-back new: write-combining > mtrr: type mismatch for e0000000,2000 old: write-back new: write-combining Vesafb defaults to write-combining mtrr. But the memory range is already set to write-back so mtrr_check() spewed the above messages. I don't think it has any ill effects, but if you want to eliminate the above messages, tell vesafb to also use write-back mtrr by adding the boot option "mtrr:2" (or nomtrr). I think I'll submit a documentation patch. Tony