Jetpack/kernel/kernel-4.9/rt-patches/0248-kernel-printk-Don-t-tr...

49 lines
1.4 KiB
Diff

From 0195f7a7ae8a37569302be47adb1e44da4ed7042 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 19 May 2016 17:45:27 +0200
Subject: [PATCH 248/352] kernel/printk: Don't try to print from IRQ/NMI region
On -RT we try to acquire sleeping locks which might lead to warnings
from lockdep or a warn_on() from spin_try_lock() (which is a rtmutex on
RT).
We don't print in general from a IRQ off region so we should not try
this via console_unblank() / bust_spinlocks() as well.
Change-Id: Ib49792ab77e0096c4d6bf952bd65da344cbea79b
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/printk/printk.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 7d70671..7938094 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1656,6 +1656,11 @@ static void call_console_drivers(int level,
if (!console_drivers)
return;
+ if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) {
+ if (in_irq() || in_nmi())
+ return;
+ }
+
migrate_disable();
for_each_console(con) {
if (exclusive_console && con != exclusive_console)
@@ -2539,6 +2544,11 @@ void console_unblank(void)
{
struct console *c;
+ if (IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) {
+ if (in_irq() || in_nmi())
+ return;
+ }
+
/*
* console_unblank can no longer be called in interrupt context unless
* oops_in_progress is set to 1..
--
2.7.4