diff options
author | Gerd Hoffmann <kraxel@suse.de> | 2007-05-08 00:26:49 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:04 -0700 |
commit | 69331af79cf29e26d1231152a172a1a10c2df511 (patch) | |
tree | 0c6f805fc78c1969b8c46f02070cb9dc39f3f944 /kernel/printk.c | |
parent | 6ae9200f2cab7b328e505fc9a7021db64e0590cf (diff) | |
download | kernel_samsung_tuna-69331af79cf29e26d1231152a172a1a10c2df511.zip kernel_samsung_tuna-69331af79cf29e26d1231152a172a1a10c2df511.tar.gz kernel_samsung_tuna-69331af79cf29e26d1231152a172a1a10c2df511.tar.bz2 |
Fixes and cleanups for earlyprintk aka boot console
The console subsystem already has an idea of a boot console, using the
CON_BOOT flag. The implementation has some flaws though. The major
problem is that presence of a boot console makes register_console() ignore
any other console devices (unless explicitly specified on the kernel
command line).
This patch fixes the console selection code to *not* consider a boot
console a full-featured one, so the first non-boot console registering will
become the default console instead. This way the unregister call for the
boot console in the register_console() function actually triggers and the
handover from the boot console to the real console device works smoothly.
Added a printk for the handover, so you know which console device the
output goes to when the boot console stops printing messages.
The disable_early_printk() call is obsolete with that patch, explicitly
disabling the early console isn't needed any more as it works automagically
with that patch.
I've walked through the tree, dropped all disable_early_printk() instances
found below arch/ and tagged the consoles with CON_BOOT if needed. The
code is tested on x86, sh (thanks to Paul) and mips (thanks to Ralf).
Changes to last version: Rediffed against -rc3, adapted to mips cleanups by
Ralf, fixed "udbg-immortal" cmd line arg on powerpc.
Signed-off-by: Gerd Hoffmann <kraxel@exsuse.de>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/printk.c')
-rw-r--r-- | kernel/printk.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index 4b47e59..c4c5a29 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -931,8 +931,16 @@ void register_console(struct console *console) { int i; unsigned long flags; + struct console *bootconsole = NULL; - if (preferred_console < 0) + if (console_drivers) { + if (console->flags & CON_BOOT) + return; + if (console_drivers->flags & CON_BOOT) + bootconsole = console_drivers; + } + + if (preferred_console < 0 || bootconsole || !console_drivers) preferred_console = selected_console; /* @@ -978,8 +986,11 @@ void register_console(struct console *console) if (!(console->flags & CON_ENABLED)) return; - if (console_drivers && (console_drivers->flags & CON_BOOT)) { - unregister_console(console_drivers); + if (bootconsole) { + printk(KERN_INFO "console handover: boot [%s%d] -> real [%s%d]\n", + bootconsole->name, bootconsole->index, + console->name, console->index); + unregister_console(bootconsole); console->flags &= ~CON_PRINTBUFFER; } @@ -1030,16 +1041,11 @@ int unregister_console(struct console *console) } } - /* If last console is removed, we re-enable picking the first - * one that gets registered. Without that, pmac early boot console - * would prevent fbcon from taking over. - * + /* * If this isn't the last console and it has CON_CONSDEV set, we * need to set it on the next preferred console. */ - if (console_drivers == NULL) - preferred_console = selected_console; - else if (console->flags & CON_CONSDEV) + if (console_drivers != NULL && console->flags & CON_CONSDEV) console_drivers->flags |= CON_CONSDEV; release_console_sem(); |