Hello,
Trying to debug why the printks from the early console are not seen early.
Inspecting console_trylock_for_printk it looks like during early boot
the lock variable will be 0 due to early_boot_irqs_disabled being true.
* Looks like even the irqs_disabled_flags(flags) will be true.
* If lock is 0 then the this method returns 0 which I believe is bad.
So how are the printks expected to be printed early?
static int console_trylock_for_printk(unsigned int cpu, unsigned long flags)
__releases(&logbuf_lock)
{
#ifdef CONFIG_PREEMPT_RT_FULL
int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
!preempt_count();
#else
.....
if (lock && console_trylock()) {
retval = 1;
}
I believe console_trylock_for_printk returning 0 is bad as it looks like
the call to console_unlock() results in the
printk buffer being sent to the console . But console_unlock() will not
be invoked in vprintk if console_trylock_for_printk
returns 0.
asmlinkage int vprintk(const char *fmt, va_list args)
{
......
......
......
if (console_trylock_for_printk(this_cpu, flags)) {
#ifndef CONFIG_PREEMPT_RT_FULL
console_unlock();
#else
raw_local_irq_restore(flags);
console_unlock();
raw_local_irq_save(flags);
#endif
}
.....
}
Thanks,
Venkat
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