Re: [Ksummit-discuss] [MAINTAINER SUMMIT] How can we treat staging drivers better?

[Mauro Carvalho Chehab <mchehab+samsung@kernel.org>]

Em Mon, 10 Sep 2018 19:22:05 +0000
<Tim.Bird@sony.com> escreveu:

> > -----Original Message-----
> > From: Laurent Pinchart
> > 
> > On Monday, 10 September 2018 21:52:30 EEST Takashi Iwai wrote:  
> > > On Fri, 07 Sep 2018 21:44:54 +0200, Mauro Carvalho Chehab wrote:  
> > > > Em Wed, 05 Sep 2018 15:35:53 +0200 Takashi Iwai escreveu:  
> > > > > The staging driver is a wonderful process to promote the downstream
> > > > > code to the upstream, but I have doubt whether it's working really as
> > > > > expected for now.
> > > > >
> > > > > - Often the drivers live forever in staging although they should have
> > > > >   been moved to the upper, properly maintained, subsystems.
> > > > >
> > > > > - Code changes in staging are mostly only scratching surfaces, minor
> > > > >   code style cleanups, etc, what checkpatch suggests.
> > > > >
> > > > > - There are little communications with the corresponding subsystem;
> > > > >   already a few times I was surprised by casually finding a staging
> > > > >   driver code by grepping for preparing API changes.  
> > > >  
> ...
> > > > > - Then some drivers are pushed back after long time stay in staging
> > > > >
> > > > >   (lustre is the recent remarkable case);
> > > > >   it's understandable, but is definitely no happy end in both sides,
> > > > >   after all.  
> > > >
> > > > We had a recent case: the (really big) atomisp driver.  
> > >
> > > What was the reason of drawback, BTW?  
> > 
> > Intel pushed a huge code drop that clearly required a staging period, and
> > then
> > simply left it bitrot. No developer was committed to perform the work
> > needed
> > to de-stage the driver. I don't know whether priorities had changed internally
> > or if there were no resources from day 1, but in the end it's pretty clear
> > that if we had known beforehand of the outcome, the driver would likely not
> > have been even a staging candidate.
> >   
> > > I think it'd be helpful if we can gather more data, e.g. good examples
> > > to show how it can succeed, as well as anti-patterns to learn what
> > > makes things failing.  
> > 
> > Anti-pattern number one: push a large driver to staging knowing that you
> > won't
> > work on it anymore, and expect the community to do your work for free.
> > 
> > I would have expected a company like Intel to know better. Or, rather sadly, I
> > probably have given up on such expectations already :-S  
> 
> I thought staging was where work was done on drivers that were submitted
> to Greg's Free Linux Driver project (https://lkml.org/lkml/2007/1/29/345)
> (among other things). 
> 
> Is that project still active?  Do things still move through staging as originally
> intended?  Am I conflating two different things?
> 
> I'm not sure if Intel's driver qualifies as a Free Linux Driver project or not.
> I can think of other companies, less experienced with kernel work than Intel,
> that might still benefit from the Free Linux Driver project, and staging.
> 
> I thought the whole idea of staging was that something was better than nothing,
> and that cruddy code could be taken even if the hardware vendor didn't have
> the skills or inclination to do proper mainlining.

I guess the submitter had the intention to maintain it, but then Spectre
and Meltdown happened and he had to shift to do something else.

IMHO, it doesn't really matter if the driver to be placed in staging is
coming from the Free Linux Driver project or from anyone else.
For me, the major requirement is that, by the time it is submitted, 
someone should want to make it to follow the upstream rules. If not,
well, we can just drop it after a while.

That's said, I would be expecting (or either desiring) that a vendor that
works well with the community on other areas would have developed 
a camera driver using upstream first approach, but we know that
not all development teams think the same.

Thanks,
Mauro