From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757084Ab3KHKg5 (ORCPT ); Fri, 8 Nov 2013 05:36:57 -0500 Received: from arkanian.console-pimps.org ([212.110.184.194]:60118 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756648Ab3KHKgy (ORCPT ); Fri, 8 Nov 2013 05:36:54 -0500 Date: Fri, 8 Nov 2013 10:36:48 +0000 From: Matt Fleming To: Dave Young Cc: matt.fleming@intel.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] efi earlyprintk fix Message-ID: <20131108103648.GA2318@console-pimps.org> References: <20131103121647.GA4770@dhcp-16-126.nay.redhat.com> <20131104103739.GD21688@console-pimps.org> <20131104125853.GB5118@dhcp-16-126.nay.redhat.com> <20131106092335.GA3952@dhcp-16-126.nay.redhat.com> <20131106093832.GC22856@console-pimps.org> <20131107120906.GB4116@dhcp-16-126.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131107120906.GB4116@dhcp-16-126.nay.redhat.com> 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 Thu, 07 Nov, at 08:09:06PM, Dave Young wrote: > Here is my debug message about the efifb params (all hex values): > [ 0.000000] efi fb lfb width: 280 > [ 0.000000] efi fb lfb height: 1e0 > [ 0.000000] efi fb lfb base: e0000000 > [ 0.000000] efi fb lfb linelength: a00 > [ 0.000000] efi fb font height: 10 > [ 0.000000] efi fb font width: 8 > > The problem looks related to the pr_cont(), here is what I observed: > [ 0.000000] efi: EFI v2.00 by Lenovo > ACPI=0xdabfe000 ACPI 2.0=0xdabfe014 SMBIOS=0xdaa9e000 > [ 0.000000] efi: > > After relooking the code, below fix is more reasonable than my original one, > But I still confused why it only happens on this machine. Dave, could you try this patch? --- diff --git a/arch/x86/platform/efi/early_printk.c b/arch/x86/platform/efi/early_printk.c index 6599a0027b76..81b506d5befd 100644 --- a/arch/x86/platform/efi/early_printk.c +++ b/arch/x86/platform/efi/early_printk.c @@ -142,7 +142,7 @@ early_efi_write(struct console *con, const char *str, unsigned int num) efi_y += font->height; } - if (efi_y + font->height >= si->lfb_height) { + if (efi_y + font->height > si->lfb_height) { u32 i; efi_y -= font->height; -- Matt Fleming, Intel Open Source Technology Center