Re: [RFC][PATCHv5 07/13] printk: register syscore notifier

Sergey Senozhatsky
2017-08-16T06:55:31Z

On (08/15/17 13:56), Rafael J. Wysocki wrote:
[..]
> > +static int printk_syscore_suspend(void)
> > +{
> > + printk_emergency_begin();
> > + return 0;
> > +}
>
> Somebody looking at suspend/resume code paths only will be wondering why
> you need this, because we should be in the emergency mode already when
> it is called.
>
> It would be good to add a comment about the kexec context here.

ok, will add.

> > +static void printk_syscore_resume(void)
> > +{
> > + printk_emergency_end();
> > +}
>
> This will turn the emergency mode off during resume before the notifier
> added by the previous patch AFAICS. Is this intentional?

emergency modes can nest. so it's OK to have

printk_emergency_begin() +1 // on
printk_emergency_begin() +1
printk_emergency_end() -1
printk_emergency_end() -1 // off

or did I misunderstand your question?

-ss