Re: [PATCH] HID: usbhid: enable remote wakeup for mice

[Michael Wu]

Dear Greg,

On 2/22/2023 2:04 PM, Greg KH wrote:
> On Wed, Feb 22, 2023 at 09:39:44AM +0800, Michael Wu wrote:
> > This patch fixes a problem that USB mouse can't wake up the device that
> > enters standby.
>
> This not a problem, it is that way by design.

I got it, maybe it's a little problem to say that.

> > At present, the kernel only checks whether certain USB manufacturers
> > support wake-up, which will easily cause inconvenience to the
> > development work of other manufacturers and add unnecessary work to the
> > maintenance of kernel.
> >
> > The USB protocol supports judging whether a usb supports the wake-up
> > function, so it should be more reasonable to add a wake-up source by
> > directly checking the settings from the USB protocol.
>
> But you do not do that in this patch, why not?

I just want to explain the background of my patch, to prove we could use 
a similar way to avoid such a "disturbing" situation.
To reduce the influence, my patch enables remote wakeup for USB mouse 
devices refer to what keyboard do.

> > There was a similar issue on the keyboard before, which was fixed by
> > this patch (3d61510f4eca), but now the problem happened on the mouse.
> > This patch uses a similar idea to fix this problem.
> >
> > Signed-off-by: Michael Wu <michael@xxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/hid/usbhid/hid-core.c | 8 ++++++++
> >   drivers/hid/usbhid/usbmouse.c | 1 +
> >   2 files changed, 9 insertions(+)
> >
> > diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
> > index be4c731aaa65..d3a6755cca09 100644
> > --- a/drivers/hid/usbhid/hid-core.c
> > +++ b/drivers/hid/usbhid/hid-core.c
> > @@ -1189,6 +1189,14 @@ static int usbhid_start(struct hid_device *hid)
> >   		device_set_wakeup_enable(&dev->dev, 1);
> >   	}
> >   
> > +	/**
> > +	 * NOTE: enable remote wakeup by default for all mouse devices
> > +	 * supporting the boot protocol.
> > +	 */
> > +	if (interface->desc.bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT &&
> > +	    interface->desc.bInterfaceProtocol == USB_INTERFACE_PROTOCOL_MOUSE)
> > +		device_set_wakeup_enable(&dev->dev, 1);
>
> Sorry, but we can not take this unless it is proven that this will work
> properly for all of these devices.  Other operating systems do not do
> this last I checked, so there will be problems.

As Mario Limonciello says, they has confirmed that the Microsoft Windows 
does set a similar policy as well. Can we talk about more in this topic: 
why does Linux not support it?
Of course, if you have other great idea, I will appreciate that if we 
can have some further discussion.

> thanks,
>
> greg k-h

--
Regards,
Michael Wu