Re: [Letux-kernel] [PATCH v5 3/5] misc serdev: Add w2sg0004 (gps receiver) power control driver

From: Johan Hovold
Date: Tue Feb 27 2018 - 02:04:27 EST


On Mon, Feb 12, 2018 at 04:26:18PM +0100, Pavel Machek wrote:
> Hi!
>
> > > Let's restart this discussion and focus on the main roadblock (others
> > > are minor details which can be sorted out later).
> > >
> > > If it feels like a hack, the key issue seems to me to be the choice of
> > > the API to present the GPS data to user space. Right?
> >
> > Or even more fundamentally, does this belong in the kernel at all?
>
> Yes, it does.

But not necessarily in its current form.

> > Now, if we'd ever have a proper GPS framework that handled everything in
> > kernel space (i.e. no more gpsd) then we would be able to write kernel
> > drivers that also take care of PM. But perhaps that's unlikely to ever
> > be realised given the state of things (proprietary protocols, numerous
> > quirky implementations, etc).
>
> That is what needs to happen.
>
> > The kernel is probably not the place to be working around issues like
> > that, even if serdev at least allows for such hacks to be fairly
> > isolated in drivers (unlike some of the earlier proposals touching core
> > code).
>
> Oh, kernel is indeed right place to provide hardware abstraction --
> and that includes bug workarounds.

Right, at least when such hacks can be confined to a driver and not be
spread all over the place.

Johan