Re: [PATCH] HID: quirks: Disable runtime suspend on Microsoft Corp. Basic Optical Mouse v2.0

[Kai-Heng Feng]

Hi Oliver,

at 17:45, Oliver Neukum <oneukum@xxxxxxxx> wrote:

> Am Donnerstag, den 22.08.2019, 17:17 +0800 schrieb Kai-Heng Feng:
> > The optical sensor of the mouse gets turned off when it's runtime
> > suspended, so moving the mouse can't wake the mouse up, despite that
> > USB remote wakeup is successfully set.
> >
> > Introduce a new quirk to prevent the mouse from getting runtime
> > suspended.
>
> Hi,
>
> I am afraid this is a bad approach in principle. The device
> behaves according to spec.

Can you please point out which spec it is? Is it USB 2.0 spec?

> And it behaves like most hardware.

So seems like most hardware are broken.
Maybe a more appropriate solution is to disable RPM for all USB mice.

> If you do not want runtime PM for such devices, do not switch
> it on.

A device should work regardless of runtime PM status.

> The refcounting needs to be done correctly.

Will do.

> This patch does something that udev should do and in a
> questionable manner.

IMO if the device doesnât support runtime suspend, then it needs to be  
disabled in kernel but not workaround in userspace.

Kai-Heng

> 	Regards
> 		Oliver