[PATCH ver. 2] PM: describe kernel policy regarding wakeup defaults

[PATCH ver. 2] PM: describe kernel policy regarding wakeup defaults

[Alan Stern]

This patch (as1381b) updates a comment describing the kernel's policy
toward enabling wakeup by default.

It also makes device_set_wakeup_capable() actually do something when
CONFIG_PM isn't enabled.  It's not clear this is necessary; however if
it isn't then device_init_wakeup() and device_can_wakeup() should also
be do-nothing routines.  Furthermore, I don't expect this change to
have any noticeable effect -- but if it does then clearly the old
behavior was wrong.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>

---

Rafael, I don't know if you got the earlier version of this patch.  
This one applies against 2.6.35-rc1.



Index: usb-2.6/include/linux/pm_wakeup.h
===================================================================
--- usb-2.6.orig/include/linux/pm_wakeup.h
+++ usb-2.6/include/linux/pm_wakeup.h
@@ -29,8 +29,11 @@
 
 #ifdef CONFIG_PM
 
-/* changes to device_may_wakeup take effect on the next pm state change.
- * by default, devices should wakeup if they can.
+/* Changes to device_may_wakeup take effect on the next pm state change.
+ *
+ * By default, most devices should leave wakeup disabled.  The exceptions
+ * are devices that everyone expects to be wakeup sources: keyboards,
+ * power buttons, possibly network interfaces, etc.
  */
 static inline void device_init_wakeup(struct device *dev, bool val)
 {
@@ -59,7 +62,7 @@ static inline bool device_may_wakeup(str
 
 #else /* !CONFIG_PM */
 
-/* For some reason the next two routines work even without CONFIG_PM */
+/* For some reason the following routines work even without CONFIG_PM */
 static inline void device_init_wakeup(struct device *dev, bool val)
 {
 	dev->power.can_wakeup = val;
@@ -67,6 +70,7 @@ static inline void device_init_wakeup(st
 
 static inline void device_set_wakeup_capable(struct device *dev, bool capable)
 {
+	dev->power.can_wakeup = capable;
 }
 
 static inline bool device_can_wakeup(struct device *dev)

Re: [PATCH ver. 2] PM: describe kernel policy regarding wakeup defaults

[Rafael J. Wysocki]

On Tuesday 08 June 2010, Alan Stern wrote:
> This patch (as1381b) updates a comment describing the kernel's policy
> toward enabling wakeup by default.
> 
> It also makes device_set_wakeup_capable() actually do something when
> CONFIG_PM isn't enabled.  It's not clear this is necessary; however if
> it isn't then device_init_wakeup() and device_can_wakeup() should also
> be do-nothing routines.  Furthermore, I don't expect this change to
> have any noticeable effect -- but if it does then clearly the old
> behavior was wrong.
> 
> Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> 
> ---
> 
> Rafael, I don't know if you got the earlier version of this patch.  

I did.

> This one applies against 2.6.35-rc1.

I assume I should replace the old patch with this one.

Rafael


> Index: usb-2.6/include/linux/pm_wakeup.h
> ===================================================================
> --- usb-2.6.orig/include/linux/pm_wakeup.h
> +++ usb-2.6/include/linux/pm_wakeup.h
> @@ -29,8 +29,11 @@
>  
>  #ifdef CONFIG_PM
>  
> -/* changes to device_may_wakeup take effect on the next pm state change.
> - * by default, devices should wakeup if they can.
> +/* Changes to device_may_wakeup take effect on the next pm state change.
> + *
> + * By default, most devices should leave wakeup disabled.  The exceptions
> + * are devices that everyone expects to be wakeup sources: keyboards,
> + * power buttons, possibly network interfaces, etc.
>   */
>  static inline void device_init_wakeup(struct device *dev, bool val)
>  {
> @@ -59,7 +62,7 @@ static inline bool device_may_wakeup(str
>  
>  #else /* !CONFIG_PM */
>  
> -/* For some reason the next two routines work even without CONFIG_PM */
> +/* For some reason the following routines work even without CONFIG_PM */
>  static inline void device_init_wakeup(struct device *dev, bool val)
>  {
>  	dev->power.can_wakeup = val;
> @@ -67,6 +70,7 @@ static inline void device_init_wakeup(st
>  
>  static inline void device_set_wakeup_capable(struct device *dev, bool capable)
>  {
> +	dev->power.can_wakeup = capable;
>  }
>  
>  static inline bool device_can_wakeup(struct device *dev)
> 
> 
> 

Re: [PATCH ver. 2] PM: describe kernel policy regarding wakeup defaults

[Alan Stern]

On Tue, 8 Jun 2010, Rafael J. Wysocki wrote:

> On Tuesday 08 June 2010, Alan Stern wrote:
> > This patch (as1381b) updates a comment describing the kernel's policy
> > toward enabling wakeup by default.
> > 
> > It also makes device_set_wakeup_capable() actually do something when
> > CONFIG_PM isn't enabled.  It's not clear this is necessary; however if
> > it isn't then device_init_wakeup() and device_can_wakeup() should also
> > be do-nothing routines.  Furthermore, I don't expect this change to
> > have any noticeable effect -- but if it does then clearly the old
> > behavior was wrong.
> > 
> > Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> > 
> > ---
> > 
> > Rafael, I don't know if you got the earlier version of this patch.  
> 
> I did.
> 
> > This one applies against 2.6.35-rc1.
> 
> I assume I should replace the old patch with this one.

Yes.  If nothing else, the merge will be simpler.

Alan Stern

Re: [PATCH ver. 2] PM: describe kernel policy regarding wakeup defaults

[Rafael J. Wysocki]

On Tuesday, June 08, 2010, Alan Stern wrote:
> On Tue, 8 Jun 2010, Rafael J. Wysocki wrote:
> 
> > On Tuesday 08 June 2010, Alan Stern wrote:
> > > This patch (as1381b) updates a comment describing the kernel's policy
> > > toward enabling wakeup by default.
> > > 
> > > It also makes device_set_wakeup_capable() actually do something when
> > > CONFIG_PM isn't enabled.  It's not clear this is necessary; however if
> > > it isn't then device_init_wakeup() and device_can_wakeup() should also
> > > be do-nothing routines.  Furthermore, I don't expect this change to
> > > have any noticeable effect -- but if it does then clearly the old
> > > behavior was wrong.
> > > 
> > > Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> > > 
> > > ---
> > > 
> > > Rafael, I don't know if you got the earlier version of this patch.  
> > 
> > I did.
> > 
> > > This one applies against 2.6.35-rc1.
> > 
> > I assume I should replace the old patch with this one.
> 
> Yes.  If nothing else, the merge will be simpler.

Applied to suspend-2.6/linux-next.

Rafael