From 2d1fe03b4f144b92feda3caa5cd9d09a7e9b2878 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 cf006d40342..6705b23bdc6 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1876,6 +1876,15 @@ 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 4df9c389b21..0e977fcbf50 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include @@ -92,6 +93,31 @@ __setup("hlt", hlt_setup); extern void call_with_stack(void (*fn)(void *), void *arg, void *sp); typedef void (*phys_reset_t)(unsigned long); +#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 + /* * A temporary stack to use for CPU reset. This is static so that we * don't clobber it with the identity mapping. When running with this @@ -281,6 +307,10 @@ void machine_restart(char *cmd) { machine_shutdown(); + /* Flush the console to make sure all the relevant messages make it + * out to the console drivers */ + arm_machine_flush_console(); + arm_pm_restart(reboot_mode, cmd); /* Give a grace period for failure to restart of 1s */