On Mon, 2008-09-08 at 22:57 +0200, Rafael J. Wysocki wrote:
> On Monday, 8 of September 2008, shaohua.li@xxxxxxxxx wrote:
> > In ACPI platform, if native PME isn't enabled, GPE is used to report wakeup event.
> > ---
> > drivers/acpi/Kconfig | 9 ++++++
> > drivers/acpi/bus.c | 15 ++++++++++
> > drivers/acpi/sleep/wakeup.c | 66 ++++++++++++++++++++++++++++++++++++++++++++
> > include/acpi/acpi_bus.h | 4 ++
> > 4 files changed, 94 insertions(+)
> >
> > Index: linux/drivers/acpi/Kconfig
> > ===================================================================
> > --- linux.orig/drivers/acpi/Kconfig 2008-09-08 14:28:50.000000000 +0800
> > +++ linux/drivers/acpi/Kconfig 2008-09-08 14:29:08.000000000 +0800
> > @@ -45,6 +45,15 @@ config ACPI_SLEEP
> > depends on PM_SLEEP
> > default y
> >
> > +config ACPI_GPE_WAKEUP
> > + bool "ACPI wakeup event support"
> > + depends on PM_SLEEP && EXPERIMENTAL
> > + help
> > + Enable ACPI to detect wakeup event. For example, PCI device can
> > + invoke PME, and in ACPI platform, the PME will invoke a GPE. With
> > + the option, we can detect which device invokes wakeup event.
> > +
> > +
> > config ACPI_PROCFS
> > bool "Deprecated /proc/acpi files"
> > depends on PROC_FS
> > Index: linux/drivers/acpi/bus.c
> > ===================================================================
> > --- linux.orig/drivers/acpi/bus.c 2008-09-08 14:28:32.000000000 +0800
> > +++ linux/drivers/acpi/bus.c 2008-09-08 14:29:03.000000000 +0800
> > @@ -496,6 +496,19 @@ static int acpi_bus_check_scope(struct a
> > return 0;
> > }
> >
> > +static BLOCKING_NOTIFIER_HEAD(acpi_bus_notify_list);
> > +int register_acpi_bus_notifier(struct notifier_block *nb)
> > +{
> > + return blocking_notifier_chain_register(&acpi_bus_notify_list, nb);
> > +}
> > +EXPORT_SYMBOL_GPL(register_acpi_bus_notifier);
> > +
> > +void unregister_acpi_bus_notifier(struct notifier_block *nb)
> > +{
> > + blocking_notifier_chain_unregister(&acpi_bus_notify_list, nb);
> > +}
> > +EXPORT_SYMBOL_GPL(unregister_acpi_bus_notifier);
> > +
> > /**
> > * acpi_bus_notify
> > * ---------------
> > @@ -506,6 +519,8 @@ static void acpi_bus_notify(acpi_handle
> > int result = 0;
> > struct acpi_device *device = NULL;
> >
> > + blocking_notifier_call_chain(&acpi_bus_notify_list,
> > + type, (void *)handle);
>
> Hm, perhaps I'm too tired and I'm missing something obvious, but can you
> tell me please why that has to be a notifier chain? It looks like you add only
> one notifier to it, so seemingly it could be replaced by a direct call to a
> function like acpi_gpe_pme_handler() (with modified list of arguments).
When the notifier chain is used, it can work regardless of whether the
CONFIG_ACPI_GPE_WAKEUP is set.
If the CONFIG_ACPI_GPE_WAKEUP is set, what you said is also OK.
>
> > if (acpi_bus_get_device(handle, &device))
> > return;
> > Index: linux/drivers/acpi/sleep/wakeup.c
> > ===================================================================
> > --- linux.orig/drivers/acpi/sleep/wakeup.c 2008-09-08 14:28:55.000000000 +0800
> > +++ linux/drivers/acpi/sleep/wakeup.c 2008-09-08 15:04:23.000000000 +0800
> > @@ -142,6 +142,70 @@ void acpi_disable_wakeup_device(u8 sleep
> > spin_unlock(&acpi_device_lock);
> > }
> >
> > +#ifdef CONFIG_ACPI_GPE_WAKEUP
> > +static int acpi_gpe_pme_check(struct acpi_device *dev)
> > +{
> > + struct device *ldev;
> > +
> > + ldev = acpi_get_physical_device(dev->handle);
> > + if (!ldev)
> > + return -ENODEV;
> > + /*
> > + * AML code might already clear the event, so ignore the return value.
> > + * Actually we can't correctly detect which device invokes GPE if the
> > + * event is cleared.
> > + */
> > + if (ldev->bus->pm && ldev->bus->pm->base.wakeup_event)
> > + ldev->bus->pm->base.wakeup_event(ldev);
> > +
> > + /*
> > + * We always send the event. AML code usually identifies the exact
> > + * device of the GPE, let's trust it
> > + */
> > + device_receive_wakeup_event(ldev);
> > +
> > + put_device(ldev);
> > + return 0;
> > +}
> > +
> > +static int acpi_gpe_pme_handler(struct notifier_block *nb,
> > + unsigned long type, void *data)
> > +{
> > + int ret;
> > + acpi_handle handle = data;
> > + struct acpi_device *dev;
> > +
> > + if (type != ACPI_NOTIFY_DEVICE_WAKE)
> > + return NOTIFY_DONE;
> > +
> > + if (acpi_bus_get_device(handle, &dev))
> > + return NOTIFY_DONE;
> > +
> > + ret = acpi_gpe_pme_check(dev);
> > +
> > + acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
> > + ACPI_NOT_ISR);
> > +
>
> At which point are dev->wakeup.gpe_device and dev->wakeup.gpe_number
> determined, for example, for PCI devices, and how?
In the boot phase a PCI device will be bound with an ACPI device. In the
system based on ACPI(GPE) when a PCI device generates a wakeup event, an
ACPI interrupt will be triggered and the ACPI AML code will send the
device wakeup event to the corresponding ACPI device. In such case we
can get the gpe number for the PCI device.
>
> > + /* FIXME: spurious interrupt, disables it? */
> > + if (ret)
> > + printk(KERN_ERR"Spurious GPE %d detected\n",
> > + dev->wakeup.gpe_number);
> > +
> > + return NOTIFY_OK;
> > +}
> > +
> > +static struct notifier_block acpi_gpe_pme_nb = {
> > + .notifier_call = acpi_gpe_pme_handler,
> > +};
> > +
> > +static void acpi_init_gpe_pme(void)
> > +{
> > + register_acpi_bus_notifier(&acpi_gpe_pme_nb);
> > +}
> > +#else
> > +static inline void acpi_init_gpe_pme(void) {}
> > +#endif
> > +
> > static int __init acpi_wakeup_device_init(void)
> > {
> > struct list_head *node, *next;
> > @@ -167,6 +231,8 @@ static int __init acpi_wakeup_device_ini
> > spin_lock(&acpi_device_lock);
> > }
> > spin_unlock(&acpi_device_lock);
> > +
> > + acpi_init_gpe_pme();
> > return 0;
> > }
> >
> > Index: linux/include/acpi/acpi_bus.h
> > ===================================================================
> > --- linux.orig/include/acpi/acpi_bus.h 2008-09-08 14:28:42.000000000 +0800
> > +++ linux/include/acpi/acpi_bus.h 2008-09-08 14:29:03.000000000 +0800
> > @@ -327,6 +327,10 @@ int acpi_bus_get_private_data(acpi_handl
> > extern int acpi_notifier_call_chain(struct acpi_device *, u32, u32);
> > extern int register_acpi_notifier(struct notifier_block *);
> > extern int unregister_acpi_notifier(struct notifier_block *);
> > +
> > +extern int register_acpi_bus_notifier(struct notifier_block *nb);
> > +extern void unregister_acpi_bus_notifier(struct notifier_block *nb);
> > +
> > /*
> > * External Functions
> > */
>
> Thanks,
> Rafael
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