Fixes and cleanups for earlyprintk aka boot console.

PATCH Superseded Gerd Hoffmann 4 participants 7 messages Feb 20, 2007 – Mar 5, 2007

Subsystems (6)

PowerPC MIPS SuperH Char and misc drivers +2 more subsystems

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Gerd Hoffmann

author

2007-02-20 11:35 UTC #0 lore raw

PATCH 1/1 Fixes and cleanups for earlyprintk aka boot console.

Hi,

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The disable_early_printk() call is obsolete with that patch, explicitly disabling the early console isn't needed any more as it works automagically with that patch.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 only so far. It is probably a good idea to run it in -mm for a while to shake out any architecture issues which might show up. Comments?

cheers,

Gerd

Signature · 1 line

Gerd Hoffmann <[email protected]>

Fixes and cleanups for earlyprintk aka boot console.

The disable_early_printk() call is obsolete with that patch, explicitly disabling the early console isn't needed any more as it works automagically with that patch.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 only so far.

Signed-off-by Gerd Hoffmann <[email protected]>

Cc Jeremy Fitzhardinge <[email protected]>

---
 arch/alpha/kernel/setup.c         |    9 ---------
 arch/alpha/kernel/srmcons.c       |    2 +-
 arch/mips/cobalt/console.c        |    5 -----
 arch/mips/dec/prom/console.c      |    5 +----
 arch/mips/sgi-ip27/ip27-console.c |    5 -----
 arch/powerpc/kernel/udbg.c        |   14 +-------------
 arch/sh/kernel/early_printk.c     |   18 ++++++------------
 arch/sh64/kernel/early_printk.c   |    8 +-------
 arch/x86_64/kernel/early_printk.c |   20 +++++---------------
 drivers/char/tty_io.c             |    5 -----
 kernel/printk.c                   |   26 ++++++++++++++++----------
 11 files changed, 31 insertions(+), 86 deletions(-)

===================================================================

arch/x86_64/kernel/early_printk.c +5 ~~-15~~

Index: paravirt-2.6.20-git14-hg791/arch/x86_64/kernel/early_printk.c
===================================================================
@@ -244,22 +244,12 @@ static int __init setup_early_printk(cha
  		early_console = &simnow_console;
  		keep_early = 1;
 	}
+
+	if (keep_early)
+		early_console->flags &= ~CON_BOOT;
+	else
+		early_console->flags |= CON_BOOT;
 	register_console(early_console);
 	return 0;
 }
-
 early_param("earlyprintk", setup_early_printk);
-
-void __init disable_early_printk(void)
-{
-	if (!early_console_initialized || !early_console)
-		return;
-	if (!keep_early) {
-		printk("disabling early console\n");
-		unregister_console(early_console);
-		early_console_initialized = 0;
-	} else {
-		printk("keeping early console\n");
-	}
-}
-

kernel/printk.c +16 ~~-10~~

Index: paravirt-2.6.20-git14-hg791/kernel/printk.c
===================================================================
@@ -931,8 +931,16 @@ void register_console(struct console *co
 {
 	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 *co
 	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 *c
 		}
 	}
 
-	/* 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();

drivers/char/tty_io.c +0 -5

Index: paravirt-2.6.20-git14-hg791/drivers/char/tty_io.c
===================================================================
@@ -141,8 +141,6 @@ static DECLARE_MUTEX(allocated_ptys_lock
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
-extern void disable_early_printk(void);
-
 static void initialize_tty_struct(struct tty_struct *tty);
 
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);

@@ -3880,9 +3878,6 @@ void __init console_init(void)
 	 * set up the console device so that later boot sequences can 
 	 * inform about problems etc..
 	 */
-#ifdef CONFIG_EARLY_PRINTK
-	disable_early_printk();
-#endif
 	call = __con_initcall_start;
 	while (call < __con_initcall_end) {
 		(*call)();

arch/alpha/kernel/setup.c +0 -9

Index: paravirt-2.6.20-git14-hg791/arch/alpha/kernel/setup.c
===================================================================
@@ -744,15 +744,6 @@ setup_arch(char **cmdline_p)
 	paging_init();
 }
 
-void __init
-disable_early_printk(void)
-{
-	if (alpha_using_srm && srmcons_output) {
-		unregister_srm_console();
-		srmcons_output = 0;
-	}
-}
-
 static char sys_unknown[] = "Unknown";
 static char systype_names[][16] = {
 	"0",

arch/alpha/kernel/srmcons.c +1 -1

Index: paravirt-2.6.20-git14-hg791/arch/alpha/kernel/srmcons.c
===================================================================
@@ -300,7 +300,7 @@ static struct console srmcons = {
 	.write		= srm_console_write,
 	.device		= srm_console_device,
 	.setup		= srm_console_setup,
-	.flags		= CON_PRINTBUFFER,
+	.flags		= CON_PRINTBUFFER | CON_BOOT,
 	.index		= -1,
 };

arch/mips/cobalt/console.c +0 -5

Index: paravirt-2.6.20-git14-hg791/arch/mips/cobalt/console.c
===================================================================
@@ -40,8 +40,3 @@ void __init cobalt_early_console(void)
 
 	printk("Cobalt: early console registered\n");
 }
-
-void __init disable_early_printk(void)
-{
-	unregister_console(&cons_info);
-}

arch/mips/dec/prom/console.c +1 -4

Index: paravirt-2.6.20-git14-hg791/arch/mips/dec/prom/console.c
===================================================================
@@ -29,7 +29,7 @@ static void __init prom_console_write(st
 static struct console promcons __initdata = {
 	.name	= "prom",
 	.write	= prom_console_write,
-	.flags	= CON_PRINTBUFFER,
+	.flags	= CON_PRINTBUFFER | CON_BOOT,
 	.index	= -1,
 };

@@ -50,6 +50,3 @@ void __init unregister_prom_console(void
 		promcons_output = 0;
 	}
 }
-
-void disable_early_printk(void)
-	__attribute__((alias("unregister_prom_console")));

arch/mips/sgi-ip27/ip27-console.c +0 -5

Index: paravirt-2.6.20-git14-hg791/arch/mips/sgi-ip27/ip27-console.c
===================================================================
@@ -67,8 +67,3 @@ __init void ip27_setup_console(void)
 {
 	register_console(&ioc3_console);
 }
-
-void __init disable_early_printk(void)
-{
-	unregister_console(&ioc3_console);
-}

arch/powerpc/kernel/udbg.c +1 ~~-13~~

Index: paravirt-2.6.20-git14-hg791/arch/powerpc/kernel/udbg.c
===================================================================
@@ -142,24 +142,12 @@ static void udbg_console_write(struct co
 static struct console udbg_console = {
 	.name	= "udbg",
 	.write	= udbg_console_write,
-	.flags	= CON_PRINTBUFFER | CON_ENABLED,
+	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_BOOT,
 	.index	= -1,
 };
 
 static int early_console_initialized;
 
-void __init disable_early_printk(void)
-{
-	if (!early_console_initialized)
-		return;
-	if (strstr(boot_command_line, "udbg-immortal")) {
-		printk(KERN_INFO "early console immortal !\n");
-		return;
-	}
-	unregister_console(&udbg_console);
-	early_console_initialized = 0;
-}
-
 /* called by setup_system */
 void register_early_udbg_console(void)
 {

arch/sh/kernel/early_printk.c +6 ~~-12~~

Index: paravirt-2.6.20-git14-hg791/arch/sh/kernel/early_printk.c
===================================================================
@@ -192,20 +192,14 @@ int __init setup_early_printk(char *buf)
 	}
 #endif
 
-	if (likely(early_console))
+	if (likely(early_console)) {
+		if (keep_early)
+			early_console->flags &= ~CON_BOOT;
+		else
+			early_console->flags |= CON_BOOT;
 		register_console(early_console);
+	}
 
 	return 0;
 }
 early_param("earlyprintk", setup_early_printk);
-
-void __init disable_early_printk(void)
-{
-	if (!early_console_initialized || !early_console)
-		return;
-	if (!keep_early) {
-		printk("disabling early console\n");
-		unregister_console(early_console);
-	} else
-		printk("keeping early console\n");
-}

arch/sh64/kernel/early_printk.c +1 -7

Index: paravirt-2.6.20-git14-hg791/arch/sh64/kernel/early_printk.c
===================================================================
@@ -79,7 +79,7 @@ static struct console sh_console = {
 	.name		= "scifcon",
 	.write		= sh_console_write,
 	.setup		= sh_console_setup,
-	.flags		= CON_PRINTBUFFER,
+	.flags		= CON_PRINTBUFFER | CON_BOOT,
 	.index		= -1,
 };

@@ -97,9 +97,3 @@ void __init enable_early_printk(void)
 
 	register_console(&sh_console);
 }
-
-void disable_early_printk(void)
-{
-	unregister_console(&sh_console);
-}
-

Andrew Morton

2007-03-02 07:46 UTC #1 lore raw

Quoted 19 lines · On Tue, 20 Feb 2007 12:35:49 +0100 Gerd Hoffmann <[email protected]> wrote:

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.

Quoted 7 lines

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 only so far. It is probably a good idea to run it in -mm for a while to shake out any architecture issues which might show up. Comments?

It blows up on powerpc:

drivers/built-in.o(.init.text+0x2080): In function `.console_init':
: undefined reference to `.disable_early_printk'

and the below patch might help.

But my confidence level isn't high so I'll drop it for now. I have a feeling this will need careful testing.

arch/x86_64/kernel/early_printk.c renamed from arch/x86_64/kernel/early_printk.c~fixes-and-cleanups-for-earlyprintk-aka-boot-console-fix +0 ~~-14~~

@@ -249,17 +249,3 @@ static int __init setup_early_printk(cha
 }
 
 early_param("earlyprintk", setup_early_printk);
-
-void __init disable_early_printk(void)
-{
-	if (!early_console_initialized || !early_console)
-		return;
-	if (!keep_early) {
-		printk("disabling early console\n");
-		unregister_console(early_console);
-		early_console_initialized = 0;
-	} else {
-		printk("keeping early console\n");
-	}
-}
-

drivers/char/tty_io.c renamed from drivers/char/tty_io.c~fixes-and-cleanups-for-earlyprintk-aka-boot-console-fix +0 -9

diff -puN drivers/char/tty_io.c~fixes-and-cleanups-for-earlyprintk-aka-boot-console-fix drivers/char/tty_io.c
@@ -141,8 +141,6 @@ static DECLARE_MUTEX(allocated_ptys_lock
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
-extern void disable_early_printk(void);
-
 static void initialize_tty_struct(struct tty_struct *tty);
 
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);

@@ -3889,13 +3887,6 @@ void __init console_init(void)
 	/* Setup the default TTY line discipline. */
 	(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
 
-	/*
-	 * set up the console device so that later boot sequences can 
-	 * inform about problems etc..
-	 */
-#ifdef CONFIG_EARLY_PRINTK
-	disable_early_printk();
-#endif
 	call = __con_initcall_start;
 	while (call < __con_initcall_end) {
 		(*call)();

Gerd Hoffmann

author Acked-by Paul Mundt Acked-by Ralf Baechle

2007-03-02 09:52 UTC #2 lore raw

Quoted 6 lines · Andrew Morton

On Tue, 20 Feb 2007 12:35:49 +0100 Gerd Hoffmann <[email protected]> wrote:
It blows up on powerpc:
drivers/built-in.o(.init.text+0x2080): In function `.console_init':
: undefined reference to `.disable_early_printk'

Hmm, I think this is just a chunk being lost due to the clash with the older version of the patch submitted as part of the xen series.

Here is the most recent version. No code changes, comments updated (ack from sh and mips arch maintainers).

Last patch queue mailed by Jeremy doesn't contain this one any more, so the conflict should be gone now.

cheers,
Gerd

Signature · 1 line

Gerd Hoffmann <[email protected]>

Fixes and cleanups for earlyprintk aka boot console.

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).

Signed-off-by Gerd Hoffmann <[email protected]>

Acked-by Paul Mundt <[email protected]>

Acked-by Ralf Baechle <[email protected]>

Cc Andi Kleen <[email protected]>

Cc Alan Cox <[email protected]>

Cc Richard Henderson <[email protected]>

Cc Ivan Kokshaysky <[email protected]>

Cc Paul Mackerras <[email protected]>

Cc Benjamin Herrenschmidt <[email protected]>

Cc Jeremy Fitzhardinge <[email protected]>

---
 arch/alpha/kernel/setup.c         |    9 ---------
 arch/alpha/kernel/srmcons.c       |    2 +-
 arch/mips/cobalt/console.c        |    5 -----
 arch/mips/dec/prom/console.c      |    5 +----
 arch/mips/sgi-ip27/ip27-console.c |    5 -----
 arch/powerpc/kernel/udbg.c        |   14 +-------------
 arch/sh/kernel/early_printk.c     |   18 ++++++------------
 arch/sh64/kernel/early_printk.c   |    8 +-------
 arch/x86_64/kernel/early_printk.c |   20 +++++---------------
 drivers/char/tty_io.c             |    5 -----
 kernel/printk.c                   |   26 ++++++++++++++++----------
 11 files changed, 31 insertions(+), 86 deletions(-)

===================================================================

arch/x86_64/kernel/early_printk.c +5 ~~-15~~

@@ -244,22 +244,12 @@ static int __init setup_early_printk(cha
  		early_console = &simnow_console;
  		keep_early = 1;
 	}
+
+	if (keep_early)
+		early_console->flags &= ~CON_BOOT;
+	else
+		early_console->flags |= CON_BOOT;
 	register_console(early_console);
 	return 0;
 }
-
 early_param("earlyprintk", setup_early_printk);
-
-void __init disable_early_printk(void)
-{
-	if (!early_console_initialized || !early_console)
-		return;
-	if (!keep_early) {
-		printk("disabling early console\n");
-		unregister_console(early_console);
-		early_console_initialized = 0;
-	} else {
-		printk("keeping early console\n");
-	}
-}
-

===================================================================

kernel/printk.c +16 ~~-10~~

@@ -931,8 +931,16 @@ void register_console(struct console *co
 {
 	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 *co
 	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 *c
 		}
 	}
 
-	/* 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();

===================================================================

drivers/char/tty_io.c +0 -5

@@ -141,8 +141,6 @@ static DECLARE_MUTEX(allocated_ptys_lock
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
-extern void disable_early_printk(void);
-
 static void initialize_tty_struct(struct tty_struct *tty);
 
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);

@@ -3880,9 +3878,6 @@ void __init console_init(void)
 	 * set up the console device so that later boot sequences can 
 	 * inform about problems etc..
 	 */
-#ifdef CONFIG_EARLY_PRINTK
-	disable_early_printk();
-#endif
 	call = __con_initcall_start;
 	while (call < __con_initcall_end) {
 		(*call)();

===================================================================

arch/alpha/kernel/setup.c +0 -9

@@ -744,15 +744,6 @@ setup_arch(char **cmdline_p)
 	paging_init();
 }
 
-void __init
-disable_early_printk(void)
-{
-	if (alpha_using_srm && srmcons_output) {
-		unregister_srm_console();
-		srmcons_output = 0;
-	}
-}
-
 static char sys_unknown[] = "Unknown";
 static char systype_names[][16] = {
 	"0",

===================================================================

arch/alpha/kernel/srmcons.c +1 -1

@@ -300,7 +300,7 @@ static struct console srmcons = {
 	.write		= srm_console_write,
 	.device		= srm_console_device,
 	.setup		= srm_console_setup,
-	.flags		= CON_PRINTBUFFER,
+	.flags		= CON_PRINTBUFFER | CON_BOOT,
 	.index		= -1,
 };

===================================================================

arch/mips/cobalt/console.c +0 -5

@@ -40,8 +40,3 @@ void __init cobalt_early_console(void)
 
 	printk("Cobalt: early console registered\n");
 }
-
-void __init disable_early_printk(void)
-{
-	unregister_console(&cons_info);
-}

===================================================================

arch/mips/dec/prom/console.c +1 -4

@@ -29,7 +29,7 @@ static void __init prom_console_write(st
 static struct console promcons __initdata = {
 	.name	= "prom",
 	.write	= prom_console_write,
-	.flags	= CON_PRINTBUFFER,
+	.flags	= CON_PRINTBUFFER | CON_BOOT,
 	.index	= -1,
 };

@@ -50,6 +50,3 @@ void __init unregister_prom_console(void
 		promcons_output = 0;
 	}
 }
-
-void disable_early_printk(void)
-	__attribute__((alias("unregister_prom_console")));

===================================================================

arch/mips/sgi-ip27/ip27-console.c +0 -5

@@ -67,8 +67,3 @@ __init void ip27_setup_console(void)
 {
 	register_console(&ioc3_console);
 }
-
-void __init disable_early_printk(void)
-{
-	unregister_console(&ioc3_console);
-}

===================================================================

arch/powerpc/kernel/udbg.c +1 ~~-13~~

@@ -142,24 +142,12 @@ static void udbg_console_write(struct co
 static struct console udbg_console = {
 	.name	= "udbg",
 	.write	= udbg_console_write,
-	.flags	= CON_PRINTBUFFER | CON_ENABLED,
+	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_BOOT,
 	.index	= -1,
 };
 
 static int early_console_initialized;
 
-void __init disable_early_printk(void)
-{
-	if (!early_console_initialized)
-		return;
-	if (strstr(boot_command_line, "udbg-immortal")) {
-		printk(KERN_INFO "early console immortal !\n");
-		return;
-	}
-	unregister_console(&udbg_console);
-	early_console_initialized = 0;
-}
-
 /* called by setup_system */
 void register_early_udbg_console(void)
 {

===================================================================

arch/sh/kernel/early_printk.c +6 ~~-12~~

@@ -192,20 +192,14 @@ int __init setup_early_printk(char *buf)
 	}
 #endif
 
-	if (likely(early_console))
+	if (likely(early_console)) {
+		if (keep_early)
+			early_console->flags &= ~CON_BOOT;
+		else
+			early_console->flags |= CON_BOOT;
 		register_console(early_console);
+	}
 
 	return 0;
 }
 early_param("earlyprintk", setup_early_printk);
-
-void __init disable_early_printk(void)
-{
-	if (!early_console_initialized || !early_console)
-		return;
-	if (!keep_early) {
-		printk("disabling early console\n");
-		unregister_console(early_console);
-	} else
-		printk("keeping early console\n");
-}

===================================================================

arch/sh64/kernel/early_printk.c +1 -7

@@ -79,7 +79,7 @@ static struct console sh_console = {
 	.name		= "scifcon",
 	.write		= sh_console_write,
 	.setup		= sh_console_setup,
-	.flags		= CON_PRINTBUFFER,
+	.flags		= CON_PRINTBUFFER | CON_BOOT,
 	.index		= -1,
 };

@@ -97,9 +97,3 @@ void __init enable_early_printk(void)
 
 	register_console(&sh_console);
 }
-
-void disable_early_printk(void)
-{
-	unregister_console(&sh_console);
-}
-

Jeremy Fitzhardinge

2007-03-02 16:06 UTC #3 lore raw

Quoted 3 lines · Gerd Hoffmann

Hmm, I think this is just a chunk being lost due to the clash with the older version of the patch submitted as part of the xen series.

But I thought the old version I had posted was well and truly dropped. Isn't this problematic patch the one you posted?

Quoted 3 lines

Last patch queue mailed by Jeremy doesn't contain this one any more, so the conflict should be gone now.

Yeah, this isn't absolutely required to make Xen work, so I didn't want to confuse things by reposting it.

Gerd Hoffmann

author

2007-03-02 16:38 UTC #4 lore raw

Quoted 6 lines · Jeremy Fitzhardinge

Quoted 2 lines · Gerd Hoffmann
Hmm, I think this is just a chunk being lost due to the clash with the older version of the patch submitted as part of the xen series.
But I thought the old version I had posted was well and truly dropped. Isn't this problematic patch the one you posted?

I think what happened is (the patch attached to the "removed from -mm" mail looks like this):

- patch-v2 merged into -mm
- patch-v1 merged into -mm as part of xen series
- merge conflict, the bits which are in patch-v1 got removed from patch-v2 to solve that, both patches in -mm
- patch-v1 got removed with other xen bits due to the conflict with zachs patches.
- mm kernel has an incomplete patch-v2 now => boom.

So it isn't a problem with the original patch, it just got corrupted during conflict resolving.

cheers,
Gerd

Signature · 1 line

Gerd Hoffmann <[email protected]>

Paul Mackerras

2007-03-05 04:27 UTC #5 lore raw

In reply to Gerd Hoffmann

Quoted 8 lines · Gerd Hoffmann

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.

You have removed functionality that is useful for debugging, that 3 architectures had, namely a way to keep using the early boot console and not replace it with a console that comes later, using a kernel command line option. Perhaps you could provide a way to do that in your patch.

Paul.

Gerd Hoffmann

author

2007-03-05 07:38 UTC #6 lore raw

Quoted 11 lines · Paul Mackerras

Quoted 8 lines · Gerd Hoffmann
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.

Quoted 5 lines

You have removed functionality that is useful for debugging, that 3 architectures had, namely a way to keep using the early boot console and not replace it with a console that comes later, using a kernel command line option. Perhaps you could provide a way to do that in your patch.

--verbose please. I don't think I broke that.

I've seen code for that in i386/x86_64 and one of the other archs (via earlyprintk=foo,keep). The code clears now the CON_BOOT flag in case keep is present, which has the wanted effect: The earlyprintk console will not be replaced.

cheers,
Gerd

Signature · 1 line

Gerd Hoffmann <[email protected]>