[RFC] Wakeup for PNP

[RFC] Wakeup for PNP

[Alan Stern]

On Tue, 23 Feb 2010, Dmitry Torokhov wrote:

> Yes, I agree, we need a genric mechanism for PNP to emable wakups. It
> was discussed a bit here:
> 
> 	http://bugzilla.kernel.org/show_bug.cgi?id=8286
> 
> but David was too hung up on the fact that number of devices in ACPI
> does not map directly onto number of serio ports when i8042 is in active
> multiplexing mode that it id not go anywhere.

Does this look reasonable?  I don't know anything about PNPBIOS or 
ISAPNP, so it handles only PNPACPI.  But at least it's a starting 
point -- and it does enable my system to wake up in response to 
hitting a key.

(This combines changes to the PNP core with changes to the i8042 
drivers.  For submission they can be broken out into separate patches.)

Alan Stern


Index: usb-2.6/drivers/input/serio/i8042-x86ia64io.h
===================================================================
--- usb-2.6.orig/drivers/input/serio/i8042-x86ia64io.h
+++ usb-2.6/drivers/input/serio/i8042-x86ia64io.h
@@ -625,6 +625,7 @@ static int i8042_pnp_kbd_probe(struct pn
 	}
 
 	i8042_pnp_kbd_devices++;
+	device_set_wakeup_enable(&dev->dev, true);
 	return 0;
 }
 
@@ -646,6 +647,7 @@ static int i8042_pnp_aux_probe(struct pn
 	}
 
 	i8042_pnp_aux_devices++;
+	device_set_wakeup_enable(&dev->dev, true);
 	return 0;
 }
 
@@ -656,7 +658,7 @@ static struct pnp_device_id pnp_kbd_devi
 };
 
 static struct pnp_driver i8042_pnp_kbd_driver = {
-	.name           = "i8042 kbd",
+	.name           = "i8042-kbd",
 	.id_table       = pnp_kbd_devids,
 	.probe          = i8042_pnp_kbd_probe,
 };
@@ -676,7 +678,7 @@ static struct pnp_device_id pnp_aux_devi
 };
 
 static struct pnp_driver i8042_pnp_aux_driver = {
-	.name           = "i8042 aux",
+	.name           = "i8042-aux",
 	.id_table       = pnp_aux_devids,
 	.probe          = i8042_pnp_aux_probe,
 };
Index: usb-2.6/drivers/pnp/core.c
===================================================================
--- usb-2.6.orig/drivers/pnp/core.c
+++ usb-2.6/drivers/pnp/core.c
@@ -164,6 +164,9 @@ int __pnp_add_device(struct pnp_dev *dev
 	list_add_tail(&dev->global_list, &pnp_global);
 	list_add_tail(&dev->protocol_list, &dev->protocol->devices);
 	spin_unlock(&pnp_lock);
+	device_set_wakeup_capable(&dev->dev,
+			dev->protocol->can_wakeup &&
+			dev->protocol->can_wakeup(dev));
 	return device_register(&dev->dev);
 }
 
Index: usb-2.6/drivers/pnp/pnpacpi/core.c
===================================================================
--- usb-2.6.orig/drivers/pnp/pnpacpi/core.c
+++ usb-2.6/drivers/pnp/pnpacpi/core.c
@@ -121,12 +121,27 @@ static int pnpacpi_disable_resources(str
 }
 
 #ifdef CONFIG_ACPI_SLEEP
+static bool pnpacpi_can_wakeup(struct pnp_dev *dev)
+{
+	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
+
+	return handle && acpi_bus_can_wakeup(handle);
+}
+
 static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state)
 {
 	struct acpi_device *acpi_dev = dev->data;
 	acpi_handle handle = acpi_dev->handle;
 	int power_state;
 
+	if (device_can_wakeup(&dev->dev)) {
+		int ret;
+
+		ret = acpi_pm_device_sleep_wake(&dev->dev,
+				device_may_wakeup(&dev->dev));
+		if (ret)
+			return ret;
+	}
 	power_state = acpi_pm_device_sleep_state(&dev->dev, NULL);
 	if (power_state < 0)
 		power_state = (state.event == PM_EVENT_ON) ?
@@ -140,6 +155,8 @@ static int pnpacpi_resume(struct pnp_dev
 	struct acpi_device *acpi_dev = dev->data;
 	acpi_handle handle = acpi_dev->handle;
 
+	if (device_can_wakeup(&dev->dev))
+		acpi_pm_device_sleep_wake(&dev->dev, false);
 	return acpi_bus_set_power(handle, ACPI_STATE_D0);
 }
 #endif
@@ -150,6 +167,7 @@ struct pnp_protocol pnpacpi_protocol = {
 	.set	 = pnpacpi_set_resources,
 	.disable = pnpacpi_disable_resources,
 #ifdef CONFIG_ACPI_SLEEP
+	.can_wakeup = pnpacpi_can_wakeup,
 	.suspend = pnpacpi_suspend,
 	.resume = pnpacpi_resume,
 #endif
Index: usb-2.6/include/linux/pnp.h
===================================================================
--- usb-2.6.orig/include/linux/pnp.h
+++ usb-2.6/include/linux/pnp.h
@@ -414,6 +414,7 @@ struct pnp_protocol {
 	int (*disable) (struct pnp_dev *dev);
 
 	/* protocol specific suspend/resume */
+	bool (*can_wakeup) (struct pnp_dev *dev);
 	int (*suspend) (struct pnp_dev * dev, pm_message_t state);
 	int (*resume) (struct pnp_dev * dev);
 

Re: [RFC] Wakeup for PNP

[Bjorn Helgaas]

On Tuesday 02 March 2010 01:13:30 pm Alan Stern wrote:
> On Tue, 23 Feb 2010, Dmitry Torokhov wrote:
> 
> > Yes, I agree, we need a genric mechanism for PNP to emable wakups. It
> > was discussed a bit here:
> > 
> > 	http://bugzilla.kernel.org/show_bug.cgi?id=8286
> > 
> > but David was too hung up on the fact that number of devices in ACPI
> > does not map directly onto number of serio ports when i8042 is in active
> > multiplexing mode that it id not go anywhere.
> 
> Does this look reasonable?  I don't know anything about PNPBIOS or 
> ISAPNP, so it handles only PNPACPI.  But at least it's a starting 
> point -- and it does enable my system to wake up in response to 
> hitting a key.

I don't know much about power management, but your patch looks
reasonable to me.

> --- usb-2.6.orig/drivers/pnp/pnpacpi/core.c
> +++ usb-2.6/drivers/pnp/pnpacpi/core.c
> @@ -121,12 +121,27 @@ static int pnpacpi_disable_resources(str
>  }
>  
>  #ifdef CONFIG_ACPI_SLEEP
> +static bool pnpacpi_can_wakeup(struct pnp_dev *dev)
> +{
> +	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);

I would have used:

	struct acpi_device *acpi_dev = dev->data;
	acpi_handle handle = acpi_dev->handle;

here because that's what the rest of the PNPACPI code does.

Bjorn

Re: [RFC] Wakeup for PNP

[Alan Stern]

On Tue, 2 Mar 2010, Bjorn Helgaas wrote:

> > Does this look reasonable?  I don't know anything about PNPBIOS or 
> > ISAPNP, so it handles only PNPACPI.  But at least it's a starting 
> > point -- and it does enable my system to wake up in response to 
> > hitting a key.
> 
> I don't know much about power management, but your patch looks
> reasonable to me.

Thanks.

> > --- usb-2.6.orig/drivers/pnp/pnpacpi/core.c
> > +++ usb-2.6/drivers/pnp/pnpacpi/core.c
> > @@ -121,12 +121,27 @@ static int pnpacpi_disable_resources(str
> >  }
> >  
> >  #ifdef CONFIG_ACPI_SLEEP
> > +static bool pnpacpi_can_wakeup(struct pnp_dev *dev)
> > +{
> > +	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
> 
> I would have used:
> 
> 	struct acpi_device *acpi_dev = dev->data;
> 	acpi_handle handle = acpi_dev->handle;
> 
> here because that's what the rest of the PNPACPI code does.

Ah yes.  I just copied the code from the corresponding PCI function 
without thinking about it very much.  I'll update the patch and wait to 
hear from other people.

Alan Stern

Re: [RFC] Wakeup for PNP

[Dmitry Torokhov]

On Tue, Mar 02, 2010 at 03:13:30PM -0500, Alan Stern wrote:
> On Tue, 23 Feb 2010, Dmitry Torokhov wrote:
> 
> > Yes, I agree, we need a genric mechanism for PNP to emable wakups. It
> > was discussed a bit here:
> > 
> > 	http://bugzilla.kernel.org/show_bug.cgi?id=8286
> > 
> > but David was too hung up on the fact that number of devices in ACPI
> > does not map directly onto number of serio ports when i8042 is in active
> > multiplexing mode that it id not go anywhere.
> 
> Does this look reasonable?  I don't know anything about PNPBIOS or 
> ISAPNP, so it handles only PNPACPI.  But at least it's a starting 
> point -- and it does enable my system to wake up in response to 
> hitting a key.
> 
> (This combines changes to the PNP core with changes to the i8042 
> drivers.  For submission they can be broken out into separate patches.)
> 
> Alan Stern
> 
> 
> Index: usb-2.6/drivers/input/serio/i8042-x86ia64io.h
> ===================================================================
> --- usb-2.6.orig/drivers/input/serio/i8042-x86ia64io.h
> +++ usb-2.6/drivers/input/serio/i8042-x86ia64io.h
> @@ -625,6 +625,7 @@ static int i8042_pnp_kbd_probe(struct pn
>  	}
>  
>  	i8042_pnp_kbd_devices++;
> +	device_set_wakeup_enable(&dev->dev, true);
>  	return 0;
>  }
>  
> @@ -646,6 +647,7 @@ static int i8042_pnp_aux_probe(struct pn
>  	}
>  
>  	i8042_pnp_aux_devices++;
> +	device_set_wakeup_enable(&dev->dev, true);
>  	return 0;
>  }
>  
> @@ -656,7 +658,7 @@ static struct pnp_device_id pnp_kbd_devi
>  };
>  
>  static struct pnp_driver i8042_pnp_kbd_driver = {
> -	.name           = "i8042 kbd",
> +	.name           = "i8042-kbd",

Why is this needed? I don't think spaces are more dangerous than a colon
which we do use...

Other than that - looks reasonable to me...

-- 
Dmitry

Re: [RFC] Wakeup for PNP

[Alan Stern]

On Tue, 2 Mar 2010, Dmitry Torokhov wrote:

> > @@ -656,7 +658,7 @@ static struct pnp_device_id pnp_kbd_devi
> >  };
> >  
> >  static struct pnp_driver i8042_pnp_kbd_driver = {
> > -	.name           = "i8042 kbd",
> > +	.name           = "i8042-kbd",
> 
> Why is this needed? I don't think spaces are more dangerous than a colon
> which we do use...

This string becomes the name of a directory in sysfs.  Having a ' '
character in a directory name just doesn't seem like a good idea; at
the very least it's likely to confuse shell scripts.  (A ':' character
is a lot less subject to misinterpretation.)  I could change the '-' to 
':' if you prefer.

> Other than that - looks reasonable to me...

Thanks.  I'll separate out the driver name change from the rest of the 
patch.

There are a couple of questions remaining.  The patch enables wakeup on 
the i8042-aux device -- is this a good idea?  I haven't tested that 
part of it yet, but we wouldn't want suspended systems waking up just 
because somebody moves the mouse around.  On the other hand, on some 
machines (like mine!) it may not be possible to enable keyboard-wakeup 
without also enabling mouse-wakeup, since they use the same GPE.

Also, the patch effectively tells the kernel that ISAPNP and PNPBIOS 
devices are incapable of issuing wakeup requests.  Is that going to 
cause trouble for people?  Would it be better to change the patch so 
that it doesn't call device_set_wakeup_capable() if 
dev->protocol->can_wakeup isn't defined?

Alan Stern

Re: [RFC] Wakeup for PNP

[Dmitry Torokhov]

Hi Alan,

On Wed, Mar 03, 2010 at 10:29:09AM -0500, Alan Stern wrote:
> On Tue, 2 Mar 2010, Dmitry Torokhov wrote:
> 
> > > @@ -656,7 +658,7 @@ static struct pnp_device_id pnp_kbd_devi
> > >  };
> > >  
> > >  static struct pnp_driver i8042_pnp_kbd_driver = {
> > > -	.name           = "i8042 kbd",
> > > +	.name           = "i8042-kbd",
> > 
> > Why is this needed? I don't think spaces are more dangerous than a colon
> > which we do use...
> 
> This string becomes the name of a directory in sysfs.  Having a ' '
> character in a directory name just doesn't seem like a good idea; at
> the very least it's likely to confuse shell scripts.  (A ':' character
> is a lot less subject to misinterpretation.)  I could change the '-' to 
> ':' if you prefer.
> 

We have not heard complains about this causing trouble ever since PNP
support was added (so what 5 years at least?). At this point I'd be more
worried about breaking existing users...

Thanks.

-- 
Dmitry