From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030438Ab2COOtf (ORCPT ); Thu, 15 Mar 2012 10:49:35 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:59639 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030267Ab2COOtc (ORCPT ); Thu, 15 Mar 2012 10:49:32 -0400 Date: Thu, 15 Mar 2012 14:51:25 +0000 From: Alan Cox To: Matthew Garrett Cc: "H. Peter Anvin" , linux-kernel@vger.kernel.org, x86@kernel.org, matt.fleming@intel.com Subject: Re: [PATCH] EFI: Only set regions uncacheable if they support it Message-ID: <20120315145125.3e46586c@pyramind.ukuu.org.uk> In-Reply-To: <20120315144236.GB4650@srcf.ucam.org> References: <1331819798-1955-1-git-send-email-mjg@redhat.com> <4F61F5E6.8060509@zytor.com> <20120315140708.GA3395@srcf.ucam.org> <4F61FA14.6020203@zytor.com> <20120315142445.GA4357@srcf.ucam.org> <4F61FC8E.8070109@zytor.com> <20120315143308.GA4382@srcf.ucam.org> <4F61FE7E.9060600@zytor.com> <20120315144236.GB4650@srcf.ucam.org> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 15 Mar 2012 14:42:36 +0000 Matthew Garrett wrote: > On Thu, Mar 15, 2012 at 07:36:46AM -0700, H. Peter Anvin wrote: > > > I would still really like to understand why we're seeing #MCs... that's > > bothersome all by itself. > > The region is the legacy video RAM, so I can imagine there being > something magic about it. Presumably by the point we are booting the firmware and our own early activities mean the pages are already marked write-combine and in our CPU caches somewhere. Is the current boot code flushing any legacy video mappings from cache before it plays with the cachability ? Alan