Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756660Ab2HWH21 (ORCPT ); Thu, 23 Aug 2012 03:28:27 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:59514 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755894Ab2HWH2Y (ORCPT ); Thu, 23 Aug 2012 03:28:24 -0400 MIME-Version: 1.0 X-Originating-IP: [173.13.129.225] In-Reply-To: <20120709182018.18165.98339.stgit@bhelgaas.mtv.corp.google.com> References: <20120709181745.18165.93914.stgit@bhelgaas.mtv.corp.google.com> <20120709182018.18165.98339.stgit@bhelgaas.mtv.corp.google.com> Date: Thu, 23 Aug 2012 00:28:23 -0700 Message-ID: Subject: Re: [PATCH 1/2] PCI: leave MEM and IO decoding disabled during 64-bit BAR sizing, too From: Olof Johansson To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Jacob Pan , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Jesse Barnes , Ivan Kokshaysky , Matthew Wilcox , Robert Hancock , linuxppc-dev Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1398 Lines: 34 Hi, On Mon, Jul 9, 2012 at 11:20 AM, Bjorn Helgaas wrote: > After 253d2e5498, we disable MEM and IO decoding for most devices while we > size 32-bit BARs. However, we restore the original COMMAND register before > we size the upper 32 bits of 64-bit BARs, so we can still cause a conflict. > > This patch waits to restore the original COMMAND register until we're > completely finished sizing the BAR. > > Reference: https://lkml.org/lkml/2007/8/25/154 > Signed-off-by: Bjorn Helgaas This patch causes boot lockup on PA Semi hardware, since it disables the bar on the UART that is used for console, and it has printks between the old and the new re-enable location. If I boot with 'debug' level for printk, I hit this. If I boot with just regular console args, I don't. I'm guessing any other platform that uses MMIO-based UART on PCI for console will have similar issues. I can verify on Chrome OS x86 hardware tomorrow if legacy powerpc isn't important enough to care about. :-) I have no proposal for a fix for this. Can you please consider reverting for 3.6 unless someone has a better idea? -Olof -- 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/