Messages in this thread | | | Subject | Re: [PATCH v2] leds: heartbeat: stop on shutdown | From | Shuah Khan <> | Date | Tue, 24 Apr 2012 09:24:34 -0600 |
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On Tue, 2012-04-24 at 17:07 +0200, Alexander Holler wrote: > A halted kernel should not show a heartbeat. > > Signed-off-by: Alexander Holler <holler@ahsoftware.de> > --- > drivers/leds/ledtrig-heartbeat.c | 18 +++++++++++++++++- > 1 files changed, 17 insertions(+), 1 deletions(-) > > diff --git a/drivers/leds/ledtrig-heartbeat.c b/drivers/leds/ledtrig-heartbeat.c > index 759c0bb..1c05bd9 100644 > --- a/drivers/leds/ledtrig-heartbeat.c > +++ b/drivers/leds/ledtrig-heartbeat.c > @@ -18,6 +18,7 @@ > #include <linux/timer.h> > #include <linux/sched.h> > #include <linux/leds.h> > +#include <linux/reboot.h> > #include "leds.h" > > struct heartbeat_trig_data { > @@ -101,13 +102,28 @@ static struct led_trigger heartbeat_led_trigger = { > .deactivate = heartbeat_trig_deactivate, > }; > > +static int heartbeat_reboot_notifier(struct notifier_block *nb, > + unsigned long code, void *unused) > +{ > + led_trigger_unregister(&heartbeat_led_trigger); > + return NOTIFY_DONE; > +} > + > +static struct notifier_block heartbeat_reboot_nb = { > + .notifier_call = heartbeat_reboot_notifier, > +}; > + > static int __init heartbeat_trig_init(void) > { > - return led_trigger_register(&heartbeat_led_trigger); > + int rc = led_trigger_register(&heartbeat_led_trigger); > + if( ! rc ) > + register_reboot_notifier(&heartbeat_reboot_nb);
Do you need to check return value here? I see return value being checked in some places in the kernel and not in others. Not checking is fine for now since register_reboot_notifier() always returns 0.
Maybe adding return handling might not be a bad idea to be consistent with other places that do check.
FYI - Andrew Morton is handling led patches these days. You might want to send include him <akpm@linux-foundation.org>
> + return rc; > } > > static void __exit heartbeat_trig_exit(void) > { > + unregister_reboot_notifier(&heartbeat_reboot_nb); > led_trigger_unregister(&heartbeat_led_trigger); > } >
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