[PATCH] PM: adjust comment regarding default wakeup policy

[PATCH] PM: adjust comment regarding default wakeup policy

[Alan Stern]

This patch (as1381) 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>
CC: David Brownell <david-b@pacbell.net>

---

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
@@ -27,8 +27,11 @@
 
 #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, int val)
 {
@@ -57,13 +60,16 @@ static inline int device_may_wakeup(stru
 
 #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, int val)
 {
 	dev->power.can_wakeup = !!val;
 }
 
-static inline void device_set_wakeup_capable(struct device *dev, int val) { }
+static inline void device_set_wakeup_capable(struct device *dev, int val)
+{
+	dev->power.can_wakeup = !!val;
+}
 
 static inline int device_can_wakeup(struct device *dev)
 {

Re: [PATCH] PM: adjust comment regarding default wakeup policy

[Rafael J. Wysocki]

On Friday 21 May 2010, Alan Stern wrote:
> This patch (as1381) 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>
> CC: David Brownell <david-b@pacbell.net>

OK by me.

Do you want me to push that in this merge window?

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
> @@ -27,8 +27,11 @@
>  
>  #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, int val)
>  {
> @@ -57,13 +60,16 @@ static inline int device_may_wakeup(stru
>  
>  #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, int val)
>  {
>  	dev->power.can_wakeup = !!val;
>  }
>  
> -static inline void device_set_wakeup_capable(struct device *dev, int val) { }
> +static inline void device_set_wakeup_capable(struct device *dev, int val)
> +{
> +	dev->power.can_wakeup = !!val;
> +}
>  
>  static inline int device_can_wakeup(struct device *dev)
>  {
> 
> 
> 

Re: [PATCH] PM: adjust comment regarding default wakeup policy

[Alan Stern]

On Mon, 24 May 2010, Rafael J. Wysocki wrote:

> On Friday 21 May 2010, Alan Stern wrote:
> > This patch (as1381) 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>
> > CC: David Brownell <david-b@pacbell.net>
> 
> OK by me.
> 
> Do you want me to push that in this merge window?

No, it can wait for the window after this one.

Alan Stern