Re: [PATCH] HID: usbhid: get/put around clearing needs_remote_wakeup
From: Benson Leung
Date: Fri Nov 21 2014 - 20:00:55 EST
On Fri, Nov 14, 2014 at 1:08 AM, Oliver Neukum <oneukum@xxxxxxx> wrote:
> On Thu, 2014-11-13 at 12:16 -0800, Benson Leung wrote:
>> In usbhid_open, usb_autopm_get_interface is called
>> before setting the needs_remote_wakeup flag, and
>> usb_autopm_put_interface is called after hid_start_in.
>> However, when the device is closed in usbhid_close, the same
>> protection isn't there when clearing needs_remote_wakeup. This will
>> add that to usbhid_close as well as usbhid_stop.
> Interesting, but this has the side effect of waking devices
> that are asleep just to remove the flag.
If devices are already asleep with this flag enabled, that means that
they are presently configured for remote wake.
Waking the device in the case of a close() is appropriate because it
also has the effect of re-suspending the device with the capability
disabled, as it is no longer necessary.
Software Engineer, Chrom* OS
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