Hi Laurent
> > > I tried to reproduce the problem, starting with drm-next which seems to
> > > work
> > > fine, moving to renesas-drivers-2018-10-09-v4.19-rc7 which also didn't
> > > exhibit any issue. I then used your kernel configuration, and got a
> > > WARN_ON
> > > \o/
> >
> > Investigations revealed that you're missing the CONFIG_COMMON_CLK_VC5=y
> > option
> > in your kernel configuration. It also revealed a bug in the error handling
> > code of the DU driver, for which I have just sent "[PATCH] drm: rcar-du:
> > Fix
> > external clock error checks".
>
> Thanks !!
> I tried your posted patch, and it solved Oops issue,
> and CONFIG_COMMON_CLK_VC5 solved HDMI outputs !!
Hmm...
I noticed Salvator can't boot if .config has CONFIG_COMMON_CLK_VC5.
This means, Salvator and ULCB can't use same binary so far for me
(= all modules are =y on .config).
I'm using previous attached .config + your patch + CONFIG_COMMON_CLK_VC5
Kernel will stop here on Salvator
-----------------
....
rcar-fcp fe9af000.fcp: ignoring dependency for device, assuming no driver
rcar-fcp fe9bf000.fcp: ignoring dependency for device, assuming no driver
rcar-fcp fea27000.fcp: ignoring dependency for device, assuming no driver
rcar-fcp fea2f000.fcp: ignoring dependency for device, assuming no driver
rcar-fcp fea37000.fcp: ignoring dependency for device, assuming no driver
[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[drm] No driver support for vblank timestamp query.
** stop here **
Best regards
---
Kuninori Morimoto
