* need to get the interface cycled with autopm_get/_put() to let a device sleep
@ 2015-04-15 14:33 Oliver Neukum
2015-04-15 15:07 ` Alan Stern
0 siblings, 1 reply; 2+ messages in thread
From: Oliver Neukum @ 2015-04-15 14:33 UTC (permalink / raw)
To: stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz
Cc: linux-usb-u79uwXL29TY76Z2rM5mHXA, linux-input-u79uwXL29TY76Z2rM5mHXA
Hi,
I found a problem with the close() function of usbhid.
It fails to properly suspend device that don't support
remote wake-up. The power core does not retry an autosuspend
that failed due to a lack of support for remote wake-up.
So there needs to be a _put() if the need for remote wake-up
is rescinded. The current state of affairs leads to joysticks
never going to sleep again after use.
But I am not happy with the simple solution. It needlessly
wakes up suspended devices. So, I tried using
usb_autopm_get_interface_no_resume(). To my considerable
surprise that didn't work. I cannot understand why.
So what is to be done?
Regards
Oliver
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^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: need to get the interface cycled with autopm_get/_put() to let a device sleep
2015-04-15 14:33 need to get the interface cycled with autopm_get/_put() to let a device sleep Oliver Neukum
@ 2015-04-15 15:07 ` Alan Stern
0 siblings, 0 replies; 2+ messages in thread
From: Alan Stern @ 2015-04-15 15:07 UTC (permalink / raw)
To: Oliver Neukum; +Cc: linux-usb, linux-input
On Wed, 15 Apr 2015, Oliver Neukum wrote:
> Hi,
>
> I found a problem with the close() function of usbhid.
> It fails to properly suspend device that don't support
> remote wake-up. The power core does not retry an autosuspend
> that failed due to a lack of support for remote wake-up.
>
> So there needs to be a _put() if the need for remote wake-up
> is rescinded. The current state of affairs leads to joysticks
> never going to sleep again after use.
>
> But I am not happy with the simple solution. It needlessly
> wakes up suspended devices. So, I tried using
> usb_autopm_get_interface_no_resume(). To my considerable
> surprise that didn't work. I cannot understand why.
In what way did it not work?
> So what is to be done?
Start with a little debugging. When you do the put, what happens
inside autosuspend_check()?
Alan Stern
^ permalink raw reply [flat|nested] 2+ messages in thread
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2015-04-15 14:33 need to get the interface cycled with autopm_get/_put() to let a device sleep Oliver Neukum
2015-04-15 15:07 ` Alan Stern
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