Re: [Ksummit-discuss] [media-submaintainers] [MAINTAINERS SUMMIT] Pull network and Patch Acceptance Consistency

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

Em Wed, 19 Jun 2019 17:48:08 +0300
Laurent Pinchart <laurent.pinchart@ideasonboard.com> escreveu:

> Hi Mauro,
> 
> On Wed, Jun 19, 2019 at 11:39:02AM -0300, Mauro Carvalho Chehab wrote:
> > Em Wed, 19 Jun 2019 10:33:23 +0200 Daniel Vetter escreveu:  
> > > On Wed, Jun 19, 2019 at 9:56 AM Dan Carpenter wrote:  
> > > > On Mon, Jun 17, 2019 at 10:31:15AM -0300, Mauro Carvalho Chehab wrote:    
> > > > > Also, usually, the bots don't build with W=1, as, on most subsystems,
> > > > > this cause lots of warnings[1].
> > > > >
> > > > > [1] On media, we have zero warnings with W=1.  
> > > >
> > > > We could ask the kbuild devs if they would consider making W=1 a per
> > > > tree option.    
> > > 
> > > No need to ask, just add a Kconfig which sets additional cflags for
> > > you for your tree and your good. The usual combinatorial testing will
> > > discover the new warnings. That's at least what we do for i915.ko
> > > (including -Werror). Gets the job done.  
> > 
> > While this works, having a W=1 per tree would, IMHO, work better, as,
> > as new warnings get added to W=1, we'll get those for free.
> > 
> > -
> > 
> > I don't like the idea of having -Werror being automatically added, as
> > this may cause problems when people try to compile with a different
> > compiler version - or on some weird architectures.  
> 
> It's not automatic though, if it depends on a Kconfig option that is
> disabled by default. The built bots can enable it, while users would
> ignore it. That being said, having it as a per-tree build bot option
> should work as well.

Having a Kconfig option is OK.

What I'm saying is that I don't like the idea of having something
like:

	ccflags-y := -Werror

Unconditionally added on some Makefile. Having it depending on a Kconfig
option (or manually added with something like "make CFLAGS=-Werror") is OK.

We had -Werror unconditionally enabled in the past on a couple of
Makefiles under media.

-

It sounds, however, that there's not a consensus with that regards, as
some subsystems enableit unconditionally:

	ccflags-y := -Werror

Others enable when there's some other make option:

	ifeq (, $(findstring -W,$(EXTRA_CFLAGS)))
		ccflags-y += -Werror
	endif

And yet other ones have their own subsystem-specific option to
enable it:

	ccflags-$(CONFIG_PPC_WERROR)  += -Werror


Thanks,
Mauro