Re: [linux-pm] [PATCH 8/9] Input: Block suspend while event queueis not empty.

[Alan Stern]

On Sun, 25 Apr 2010, Rafael J. Wysocki wrote:

> On Saturday 24 April 2010, Alan Stern wrote:
> > On Fri, 23 Apr 2010, Arve Hjønnevåg wrote:
> > 
> > > On Fri, Apr 23, 2010 at 2:08 PM, Dmitry Torokhov
> > > <dmitry.torokhov@xxxxxxxxx> wrote:
> > > > On Friday 23 April 2010 01:56:25 pm Randy Dunlap wrote:
> > > >> On Thu, 22 Apr 2010 18:08:57 -0700 Arve Hjønnevåg wrote:
> > > >> > Add an ioctl, EVIOCSSUSPENDBLOCK, to enable a suspend_blocker that will
> > > >> > block suspend while the event queue is not empty. This allows userspace
> > > >> > code to process input events while the device appears to be asleep.

> > Is there some reason why this feature needs to be enabled by an 
> > ioctl?  Why not make this suspend blocker permanently enabled?
> 
> The ioctl is there so that user space can use suspend blockers, which is
> needed because only user space know that some activities are going to continue
> and therefore the system should not be suspended (like playing music "in the
> background").

No, you're thinking of a different ioctl: SUSPEND_BLOCKER_IOCTL_BLOCK.  
This one (EVIOCSSUSPENDBLOCK) is present _only_ to enable one specific
suspend blocker, which is activated when the input event queue is
non-empty.  I don't see any reason why it shouldn't be enabled all the
time.

Alan Stern

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