On Wed, 26 Sep 2007, Arnd Bergmann wrote:
> On Wednesday 26 September 2007, Ishizaki Kou wrote:
>
> > +static irqreturn_t beat_power_event(int virq, void *arg)
> > +{
> > + printk(KERN_DEBUG "Beat: power button pressed\n");
> > + beat_pm_poweroff_flag = 1;
> > + if (kill_cad_pid(SIGINT, 1)) {
> > + /* Just in case killing init process failed */
> > + beat_power_off();
> > + }
> > + return IRQ_HANDLED;
> > +}
>
> I think this should call ctrl_alt_del() instead of doing
> kill_cad_pid() directly.
Agree.
> Also, I think you should better not call the low-level
> beat_power_off() function, but rather a high-level function
> that goes through the reboot notifiers first.
>
> kernel_restart() seems appropriate for that.
Now a comment to this one says:
* This is not safe to call in interrupt context.
and AFAIU, this is called from an interrupt. Am I missing anything or
would this be wrong to call kernel_restart() here?
> > +static irqreturn_t beat_reset_event(int virq, void *arg)
> > +{
> > + printk(KERN_DEBUG "Beat: reset button pressed\n");
> > + beat_pm_poweroff_flag = 0;
> > + if (kill_cad_pid(SIGINT, 1)) {
> > + /* Just in case killing init process failed */
> > + beat_restart(NULL);
> > + }
> > + return IRQ_HANDLED;
> > +}
>
> same here, except calling kernel_halt() in the end.
kernel_halt() doesn't have a similar comment, but it does call the
kernel_shutdown_prepare() too, so, seems like it should not be called from
an interrupt either?
Now, another question, is it generally good to hard-wire "reset" and
"power-off" buttons in the kernel? Isn't it better to just register them
as input event sources and let userspace (power-management daemon) decide
what to do with them? Like poweroff / reboot / suspend / hibernate / ...
Thanks
Guennadi
---
Guennadi Liakhovetski
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