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

From: Kai-Heng Feng
Date: Thu Aug 22 2019 - 09:45:21 EST


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