From a66187787262dd803174c31c9ca91906c4d5c695 Mon Sep 17 00:00:00 2001 From: Dima Zavin Date: Tue, 23 Aug 2011 15:56:50 -0700 Subject: [PATCH] ARM: add option to flush console before reboot If the console_lock was held while the system was rebooted, the messages in the temporary logbuffer would not have propogated to all the console drivers. This force releases the console lock if it failed to be acquired. Change-Id: I193dcf7b968be17966833e50b8b8bc70d5d9fe89 Signed-off-by: Dima Zavin --- arch/arm/Kconfig | 9 +++++++++ arch/arm/kernel/process.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 91c84cb..ff8424b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1685,6 +1685,15 @@ config DEPRECATED_PARAM_STRUCT This was deprecated in 2001 and announced to live on for 5 years. Some old boot loaders still use this way. +config ARM_FLUSH_CONSOLE_ON_RESTART + bool "Force flush the console on restart" + help + If the console is locked while the system is rebooted, the messages + in the temporary logbuffer would not have propogated to all the + console drivers. This option forces the console lock to be + released if it failed to be acquired, which will cause all the + pending messages to be flushed. + endmenu menu "Boot options" diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 919de7c..34fca2e 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -90,8 +91,37 @@ static int __init hlt_setup(char *__unused) __setup("nohlt", nohlt_setup); __setup("hlt", hlt_setup); +#ifdef CONFIG_ARM_FLUSH_CONSOLE_ON_RESTART +void arm_machine_flush_console(void) +{ + printk("\n"); + pr_emerg("Restarting %s\n", linux_banner); + if (console_trylock()) { + console_unlock(); + return; + } + + mdelay(50); + + local_irq_disable(); + if (!console_trylock()) + pr_emerg("arm_restart: Console was locked! Busting\n"); + else + pr_emerg("arm_restart: Console was locked!\n"); + console_unlock(); +} +#else +void arm_machine_flush_console(void) +{ +} +#endif + void arm_machine_restart(char mode, const char *cmd) { + /* Flush the console to make sure all the relevant messages make it + * out to the console drivers */ + arm_machine_flush_console(); + /* Disable interrupts first */ local_irq_disable(); local_fiq_disable(); -- 2.7.4