From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751358AbaHITXK (ORCPT ); Sat, 9 Aug 2014 15:23:10 -0400 Received: from mail-wi0-f173.google.com ([209.85.212.173]:61285 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751055AbaHITXG (ORCPT ); Sat, 9 Aug 2014 15:23:06 -0400 Date: Sat, 9 Aug 2014 20:23:02 +0100 From: Matt Fleming To: Yinghai Lu Cc: Mantas =?utf-8?Q?Mikul=C4=97nas?= , Matt Fleming , Linux Kernel Mailing List , linux-efi@vger.kernel.org Subject: Re: Loading initrd above 4G causes freeze on boot Message-ID: <20140809192302.GJ15082@console-pimps.org> References: <53E62EEF.9040801@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 09 Aug, at 09:44:55AM, Yinghai Lu wrote: > On Sat, Aug 9, 2014 at 7:23 AM, Mantas Mikulėnas wrote: > > As of commit 4bf7111f5016 ("x86/efi: Support initrd loaded above 4G"), > > the kernel freezes at the earliest possible moment when trying to boot > > via UEFI on my Asus laptop. (It still boots via BIOS.) > > > > If I revert that commit on current master (c309bfa9b481), it boots > > correctly again [although I see "setup_efi_pci() failed" being printed]. > > > > (Seems like it freezes when handle_cmdline_files() attempts to read > > the last chunk of the initramfs -- the last call to efi_file_read() > > never returns. Figuring out why that happens is beyond me, though.) > > > > Matt found that efi_file_read()/firmware has problem that could not do > several reading. Please check if reverting that commit have any > difference. > > --- > I spent some time playing around with this bug and it appears to be > triggered by the read-a-chunk-at-a-time logic in handle_cmdline_files(), > (which is itself a bug workaround) introduced here, > > commit 2d2da60fb40a > Author: Maarten Lankhorst > Date: Fri Dec 16 13:30:58 2011 +0100 > > x86, efi: Break up large initrd reads Right, I committed a patch to workaround this problem here, http://git.kernel.org/cgit/linux/kernel/git/mfleming/efi.git/commit/?h=next&id=1c24a2bef39f041eb578189207240d0457ef0ac3 since on my ASUS machine the combination of breaking up initrd reads into chunks and reading into a buffer above 4G actually triggers a whole new bug. Mantas, could you try out the patch referenced above and pass "efi=nochunk" on the command line to the EFI boot stub. I'm hoping that fixes your problem. -- Matt Fleming, Intel Open Source Technology Center