On Sun, 2007-12-16 at 20:15 +0100, Rafael J. Wysocki wrote:
> > + *
> > + * Unfortunately we cannot do a timeout because then we'd
> > + * suspend again right away if the process that had apm_bios
> > + * open and that we timed out waiting for "acknowledges" the
> > + * event after we have resumed. If suspend doesn't work because
> > + * of a rogue process, just kill that process.
> > + *
> > + * FIXME: is the suspends_pending == 1 test racy?
I think we can do the timeout thing easily... Just mark the fd's that
haven't ack'ed with a flag that makes us ignore the next ack...
Ben.
> Make suspends_pending atomic? Then, you'd not need the locking around it.
>
> > + */
> > + err = wait_event_interruptible(apm_suspend_waitqueue,
> > + suspends_pending == 1);
> > +
> > + mutex_lock(&state_lock);
> > + suspends_pending--;
> > + mutex_unlock(&state_lock);
> > +
> > + if (!err)
> > + return NOTIFY_OK;
> > +
> > + /* interrupted by signal */
> > + return NOTIFY_BAD;
> > +
> > + case PM_POST_SUSPEND:
> > + /* TODO: maybe grab error code, needs core changes */
> > + apm_after_resume(0);
> > + return NOTIFY_OK;
> > +
> > + default:
> > + return NOTIFY_DONE;
> > + }
> > +}
> > +
> > +struct notifier_block apm_notif_block = {
> > + .notifier_call = apm_suspend_notifier,
> > +};
> > +
> > static int __init apm_init(void)
> > {
> > int ret;
> > @@ -588,7 +671,7 @@ static int __init apm_init(void)
> > if (IS_ERR(kapmd_tsk)) {
> > ret = PTR_ERR(kapmd_tsk);
> > kapmd_tsk = NULL;
> > - return ret;
> > + goto out;
> > }
> > wake_up_process(kapmd_tsk);
> >
> > @@ -597,16 +680,27 @@ static int __init apm_init(void)
> > #endif
> >
> > ret = misc_register(&apm_device);
> > - if (ret != 0) {
> > - remove_proc_entry("apm", NULL);
> > - kthread_stop(kapmd_tsk);
> > - }
> > + if (ret)
> > + goto out_stop;
> > +
> > + ret = register_pm_notifier(&apm_notif_block);
> > + if (ret)
> > + goto out_unregister;
> >
> > + return 0;
> > +
> > + out_unregister:
> > + misc_deregister(&apm_device);
> > + out_stop:
> > + remove_proc_entry("apm", NULL);
> > + kthread_stop(kapmd_tsk);
> > + out:
> > return ret;
> > }
> >
> > static void __exit apm_exit(void)
> > {
> > + unregister_pm_notifier(&apm_notif_block);
> > misc_deregister(&apm_device);
> > remove_proc_entry("apm", NULL);
> >
> > --- everything.orig/kernel/power/main.c 2007-12-16
> 15:23:18.689514811 +0100
> > +++ everything/kernel/power/main.c 2007-12-16 15:31:06.179512207
> +0100
> > @@ -25,6 +25,7 @@
> > #include "power.h"
> >
> > BLOCKING_NOTIFIER_HEAD(pm_chain_head);
> > +EXPORT_SYMBOL_GPL(pm_chain_head);
> >
> > DEFINE_MUTEX(pm_mutex);
>
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