From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754655Ab0DTQV4 (ORCPT ); Tue, 20 Apr 2010 12:21:56 -0400 Received: from imr3.ericy.com ([198.24.6.13]:40817 "EHLO imr3.ericy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754499Ab0DTQVy (ORCPT ); Tue, 20 Apr 2010 12:21:54 -0400 From: Guenter Roeck To: linux-kernel@vger.kernel.org, penberg@cs.helsinki.fi, mingo@redhat.com, x86@kernel.org CC: Guenter Roeck Subject: [PATCH v3] x86: Do not write into VGA memory space if there is no VGA device in the system Date: Tue, 20 Apr 2010 09:16:57 -0700 Message-ID: <1271780217-27472-1-git-send-email-guenter.roeck@ericsson.com> X-Mailer: git-send-email 1.7.0.87.g0901d MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ensure that early_printk() does not write into VGA memory space if there is not VGA device in the system. Signed-off-by: Guenter Roeck --- v3: Changes are now limited to early_printk.c. Functionality is retained, meaning there will still be output on the VGA console before setup_early_printk() is called, but only if a VGA device is known to exist in the system. arch/x86/kernel/early_printk.c | 17 +++++++++++++---- 1 files changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index b9c830c..783cb25 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -170,10 +170,13 @@ asmlinkage void early_printk(const char *fmt, ...) int n; va_list ap; - va_start(ap, fmt); - n = vscnprintf(buf, sizeof(buf), fmt, ap); - early_console->write(early_console, buf, n); - va_end(ap); + if (early_console && (early_console_initialized || + boot_params.screen_info.orig_video_isVGA == 1)) { + va_start(ap, fmt); + n = vscnprintf(buf, sizeof(buf), fmt, ap); + early_console->write(early_console, buf, n); + va_end(ap); + } } static inline void early_console_register(struct console *con, int keep_early) @@ -233,6 +236,12 @@ static int __init setup_early_printk(char *buf) #endif buf++; } + + /* If there is no VGA device, don't try to use it as early console. */ + if (early_console == &early_vga_console && + boot_params.screen_info.orig_video_isVGA != 1) + early_console = NULL; + return 0; } -- 1.7.0.87.g0901d