[PATCH] staging: bcm2835: fix vchiq_mmal dependencies

[Jacopo Mondi]

Hi Arnd,

On Fri, Dec 04, 2020 at 01:49:39PM +0100, Arnd Bergmann wrote:
> On Fri, Dec 4, 2020 at 11:44 AM Jacopo Mondi <jacopo at jmondi.org> wrote:
> >
> > Hi Arnd,
> >
> > On Thu, Dec 03, 2020 at 11:38:30PM +0100, Arnd Bergmann wrote:
> > > From: Arnd Bergmann <arnd at arndb.de>
> > >
> > > When the MMAL code is built-in but the vchiq core config is
> > > set to =m, the mmal code never gets built, which in turn can
> > > lead to link errors:
> >
> > My bad, I repetedly ignored the error report received from the 'kernel
> > test robot' about this. Thanks for fixing.
> >
> > For my eduction, why would the vchiq-mmal code not get build if
> > vchiq-core is set to M ? I mean, that configuration is indeed wrong,
> > as vchiq-mmal uses symbols from vchiq-core and I would expect that to
> > fail when building the kernel image, not have the other modules (as
> > bcm2835-camera) fail as a consequence when building modules.
>
>
> drivers/staging/Makefile has this line:

My bad, I only looked into drivers/staging/vc04_services/

>
> obj-$(CONFIG_BCM2835_VCHIQ)     += vc04_services/
>
> when CONFIG_BCM2835_VCHIQ=m, the kbuild infrastructure
> only enters the subdirectory while building modules, but a built-in
> mmal driver is not a loadable module, so it does not get built
> at that time. When compiling the built-in code, the subdirectory is
> not entered.

Thanks, all clear now!

>
> > > Fixes: b18ee53ad297 ("staging: bcm2835: Break MMAL support out from camera")
> > > Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> >
> > Acked-by: Jacopo Mondi <jacopo at jmondi.org>
> >
> > If you noticed this from the same error notification I recevied it
> > might be fair to report:
> > Reported-by: kernel test robot <lkp at intel.com>
>
> I had not seen that report but found it during my own testing,
> thanks for adding.
>
>       Arnd