Re: [PATCH 5/7] omapfb: omapfb_dss.h: add stubs to build with COMPILE_TEST && DRM_OMAP

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

Em Wed, 25 Apr 2018 12:47:34 +0200
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> escreveu:

> On Monday, April 23, 2018 10:55:57 AM Mauro Carvalho Chehab wrote:
> > Em Mon, 23 Apr 2018 14:47:28 +0200
> > Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> escreveu:
> >   
> > > On Friday, April 20, 2018 01:42:51 PM Mauro Carvalho Chehab wrote:  
> > > > Add stubs for omapfb_dss.h, in the case it is included by
> > > > some driver when CONFIG_FB_OMAP2 is not defined, with can
> > > > happen on ARM when DRM_OMAP is not 'n'.
> > > > 
> > > > That allows building such driver(s) with COMPILE_TEST.
> > > > 
> > > > Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>    
> > > 
> > > This patch should be dropped (together with patch #6/7) as it was
> > > superseded by a better solution suggested by Laurent:
> > > 
> > > https://patchwork.kernel.org/patch/10325193/
> > > 
> > > ACK-ed by Tomi:
> > > 
> > > https://www.spinics.net/lists/dri-devel/msg171918.html
> > > 
> > > and already merged by you (commit 7378f1149884 "media: omap2:
> > > omapfb: allow building it with COMPILE_TEST")..  
> > 
> > I "ressurected" this patch due to patch 6/7.
> > 
> > The problem with the solution already acked/merged is that
> > it works *only* if you don't try to build for ARM.
> > 
> > At the moment you want to build a FB_OMAP2-dependent driver
> > on ARM with allyesc onfig, DRM_OMAP will be true, and FB_OMAP2
> > will be disabled:
> > 
> > 	menuconfig FB_OMAP2
> >         	tristate "OMAP2+ frame buffer support"
> > 	        depends on FB
> >         	depends on DRM_OMAP = n
> > 
> > One solution might be to change the depends on to:
> >         	depends on (DRM_OMAP = n || COMPILE_TEST)
> > 
> > But someone pointed me that the above check was added to avoid building
> > duplicated symbols. So, the above would cause build failures.
> > 
> > So, in order to build for ARM with DRM_OMAP selected (allyesconfig,
> > allmodconfig), we have the following alternatives:
> > 
> > 	1) apply patch 5/7;
> > 	2) make sure that FB_OMAP2 and DRM_OMAP won't declare the
> > 	   same non-static symbols;
> > 	3) redesign FB_OMAP2 to work with DRM_OMAP built.
> > 
> > I suspect that (1) is easier.  
> 
> I agree.
> 
> You can merge this patch through your tree with:
> 
> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Thanks, I'll merge it. It would still be really cool if Tony
or someone else could find a better way for omap3isp driver to
not depend on it.

Regards,
Maur

Thanks,
Mauro