From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Thu, 29 Jun 2006 12:57:32 +0000 (+0200)
Subject: [S390] console_unblank woes.
X-Git-Tag: v2.6.18-rc1~360^2~19
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=06fa46a2fcb7e13386707a3eac74f11140a9f818;p=linux-2.6

[S390] console_unblank woes.

The software watchdog calls machine_restart from a timer function.
The s390 machine_restart calls console_unblank to flush the console
output. This is needed for panic to get the panic message printed.
If console_unblank is called in interrupt a BUG is triggered in
acquire_console_sem. That makes the software watchdog panic instead
of restarting the machine. To get around this problem the call to
console_unblank is made conditionally on !in_interrupt() ||
oops_in_progress.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index b282034452..813444aac7 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -289,19 +289,34 @@ void (*_machine_power_off)(void) = do_machine_power_off_nonsmp;
 
 void machine_restart(char *command)
 {
-	console_unblank();
+	if (!in_interrupt() || oops_in_progress)
+		/*
+		 * Only unblank the console if we are called in enabled
+		 * context or a bust_spinlocks cleared the way for us.
+		 */
+		console_unblank();
 	_machine_restart(command);
 }
 
 void machine_halt(void)
 {
-	console_unblank();
+	if (!in_interrupt() || oops_in_progress)
+		/*
+		 * Only unblank the console if we are called in enabled
+		 * context or a bust_spinlocks cleared the way for us.
+		 */
+		console_unblank();
 	_machine_halt();
 }
 
 void machine_power_off(void)
 {
-	console_unblank();
+	if (!in_interrupt() || oops_in_progress)
+		/*
+		 * Only unblank the console if we are called in enabled
+		 * context or a bust_spinlocks cleared the way for us.
+		 */
+		console_unblank();
 	_machine_power_off();
 }