Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754100AbZGTUJt (ORCPT ); Mon, 20 Jul 2009 16:09:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754072AbZGTUJp (ORCPT ); Mon, 20 Jul 2009 16:09:45 -0400 Received: from mail.windriver.com ([147.11.1.11]:36152 "EHLO mail.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754001AbZGTUJg (ORCPT ); Mon, 20 Jul 2009 16:09:36 -0400 From: Jason Wessel To: gregkh@suse.de Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Jason Wessel , Ingo Molnar , Andrew Morton , Yinghai Lu , "Eric W. Biederman" , Randy Dunlap Subject: [PATCH 05/10] printk,early_printk,console: Allow more than one early console Date: Mon, 20 Jul 2009 15:06:27 -0500 Message-Id: <1248120392-8372-6-git-send-email-jason.wessel@windriver.com> X-Mailer: git-send-email 1.6.0.3.523.g304d0 In-Reply-To: <1248120392-8372-5-git-send-email-jason.wessel@windriver.com> References: <1248120392-8372-1-git-send-email-jason.wessel@windriver.com> <1248120392-8372-2-git-send-email-jason.wessel@windriver.com> <1248120392-8372-3-git-send-email-jason.wessel@windriver.com> <1248120392-8372-4-git-send-email-jason.wessel@windriver.com> <1248120392-8372-5-git-send-email-jason.wessel@windriver.com> X-OriginalArrivalTime: 20 Jul 2009 20:06:42.0222 (UTC) FILETIME=[995B94E0:01CA0975] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6256 Lines: 202 It is very nice to be able to use one early boot device to debug another or to have multiple places you can see the early boot diagnostics, such as the vga screen or serial device. This patch changes the early_printk console device registration to allow more than one early printk device to get registered via register_console(). A corresponding change is required to the console registration code such that it will properly unregister any console marked with the CON_BOOT flag via a simple loop during a console handover or at late init time. Signed-off-by: Jason Wessel Cc: Greg KH Cc: Ingo Molnar Cc: Andrew Morton Cc: Yinghai Lu Cc: "Eric W. Biederman" Cc: Randy Dunlap --- arch/x86/kernel/early_printk.c | 65 ++++++++++++++++++++------------------- kernel/printk.c | 41 ++++++++++++++++--------- 2 files changed, 59 insertions(+), 47 deletions(-) diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index 519a5e1..2acfd3f 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -176,10 +176,19 @@ asmlinkage void early_printk(const char *fmt, ...) va_end(ap); } +static inline void early_console_register(struct console *con, int keep_early) +{ + early_console = con; + if (keep_early) + early_console->flags &= ~CON_BOOT; + else + early_console->flags |= CON_BOOT; + register_console(early_console); +} static int __init setup_early_printk(char *buf) { - int keep_early; + int keep; if (!buf) return 0; @@ -188,42 +197,34 @@ static int __init setup_early_printk(char *buf) return 0; early_console_initialized = 1; - keep_early = (strstr(buf, "keep") != NULL); - - if (!strncmp(buf, "serial", 6)) { - early_serial_init(buf + 6); - early_console = &early_serial_console; - } else if (!strncmp(buf, "ttyS", 4)) { - early_serial_init(buf); - early_console = &early_serial_console; - } else if (!strncmp(buf, "vga", 3) - && boot_params.screen_info.orig_video_isVGA == 1) { - max_xpos = boot_params.screen_info.orig_video_cols; - max_ypos = boot_params.screen_info.orig_video_lines; - current_ypos = boot_params.screen_info.orig_y; - early_console = &early_vga_console; + keep = (strstr(buf, "keep") != NULL); + + while (*buf != '\0') { + if (!strncmp(buf, "serial", 6)) { + early_serial_init(buf + 6); + early_console_register(&early_serial_console, keep); + } + if (!strncmp(buf, "ttyS", 4)) { + early_serial_init(buf + 4); + early_console_register(&early_serial_console, keep); + } + if (!strncmp(buf, "vga", 3) && + boot_params.screen_info.orig_video_isVGA == 1) { + max_xpos = boot_params.screen_info.orig_video_cols; + max_ypos = boot_params.screen_info.orig_video_lines; + current_ypos = boot_params.screen_info.orig_y; + early_console_register(&early_vga_console, keep); + } #ifdef CONFIG_EARLY_PRINTK_DBGP - } else if (!strncmp(buf, "dbgp", 4)) { - if (early_dbgp_init(buf+4) < 0) - return 0; - early_console = &early_dbgp_console; - /* - * usb subsys will reset ehci controller, so don't keep - * that early console - */ - keep_early = 0; + if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4)) + early_console_register(&early_dbgp_console, keep); #endif #ifdef CONFIG_HVC_XEN - } else if (!strncmp(buf, "xen", 3)) { - early_console = &xenboot_console; + if (!strncmp(buf, "xen", 3)) + early_console_register(&xenboot_console, keep); #endif + buf++; } - - if (keep_early) - early_console->flags &= ~CON_BOOT; - else - early_console->flags |= CON_BOOT; - register_console(early_console); return 0; } diff --git a/kernel/printk.c b/kernel/printk.c index b4d97b5..45e0cec 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1129,6 +1129,28 @@ void console_start(struct console *console) } EXPORT_SYMBOL(console_start); +static int disable_boot_consoles(void) +{ + struct console *bootconsole = console_drivers; + struct console *nextcon; + if (!bootconsole) + return 0; + while (bootconsole) { + nextcon = bootconsole->next; + if (bootconsole->flags & CON_BOOT) { + printk(KERN_INFO "turn off boot console %s%d\n", + console_drivers->name, console_drivers->index); + if (unregister_console(bootconsole) != 0) + printk(KERN_ERR "ERROR unregistering %s%d\n", + console_drivers->name, + console_drivers->index); + } + bootconsole = nextcon; + } + return 0; +} +late_initcall(disable_boot_consoles); + /* * The console driver calls this routine during kernel initialization * to register the console printing procedure with printk() and to @@ -1142,8 +1164,7 @@ void register_console(struct console *console) struct console *bootconsole = NULL; if (console_drivers) { - if (console->flags & CON_BOOT) - return; + if (console_drivers->flags & CON_BOOT) bootconsole = console_drivers; } @@ -1216,6 +1237,7 @@ void register_console(struct console *console) console->name, console->index); unregister_console(bootconsole); console->flags &= ~CON_PRINTBUFFER; + disable_boot_consoles(); } else { printk(KERN_INFO "console [%s%d] enabled\n", console->name, console->index); @@ -1280,24 +1302,13 @@ int unregister_console(struct console *console) if (console_drivers != NULL && console->flags & CON_CONSDEV) console_drivers->flags |= CON_CONSDEV; + if (!res) + console->index = -1; release_console_sem(); return res; } EXPORT_SYMBOL(unregister_console); -static int __init disable_boot_consoles(void) -{ - if (console_drivers != NULL) { - if (console_drivers->flags & CON_BOOT) { - printk(KERN_INFO "turn off boot console %s%d\n", - console_drivers->name, console_drivers->index); - return unregister_console(console_drivers); - } - } - return 0; -} -late_initcall(disable_boot_consoles); - #if defined CONFIG_PRINTK /* -- 1.6.0.3.523.g304d0 -- 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/