Re: [virtio-dev] Re: [PATCH v3] Add virtio-input driver.

From: Dmitry Torokhov
Date: Tue Mar 24 2015 - 12:05:30 EST


On Tue, Mar 24, 2015 at 04:25:14PM +0100, Gerd Hoffmann wrote:
> On Di, 2015-03-24 at 15:14 +0100, Michael S. Tsirkin wrote:
> > On Tue, Mar 24, 2015 at 02:37:24PM +0100, Gerd Hoffmann wrote:
> > > Hi,
> > >
> > > > > input layer checks it and ignores events not supported (according to the
> > > > > support bitmaps).
> > > >
> > > > Right but support bitmaps come from host too, no?
> > >
> > > Yes, but the driver will not set invalid bits (bitcount argument for the
> > > virtinput_cfg_bits() function is the number of valid bits of the
> > > specific bitmap).
> > >
> > > cheers,
> > > Gerd
> > >
> > >
> > >
> >
> > Question: does linux ever get such events from userspace
> > as opposed to sending them to userspace?
>
> Yes, it's possible using the userspace input driver
> (CONFIG_INPUT_UINPUT)

No, not through uinput (as from kernel POV uinput is also a driver), but
users can write into evdev.

Sending unknown codes is OK: events of unknown type will be dropped by
the input core, unknown event codes will be passed on; users not
recognizing event code should simply ignore it.

Thanks.

--
Dmitry
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