[PATCH] ARM: imx: drop devlinks to reset-controller node

[Philipp Zabel]

Hi Saravana,

On Tue, 2021-09-21 at 07:45 -0700, Saravana Kannan wrote:
> On Tue, Sep 21, 2021 at 5:50 AM Philipp Zabel <p.zabel at pengutronix.de> wrote:
> > Starting with commit 6b2117ad65f1 ("of: property: fw_devlink: Add
> > support for "resets" and "pwms""), the imx-drm driver fails to load
> > due to forever dormant devlinks to the reset-controller node. This
> > node is never associated with a struct device.
> > 
> > Drop those links, the reset controller is always available.
> > 
> > Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
> > ---
> >  arch/arm/mach-imx/src.c | 10 +++++++++-
> >  1 file changed, 9 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c
> > index 95fd1fbb0826..6924ac19a762 100644
> > --- a/arch/arm/mach-imx/src.c
> > +++ b/arch/arm/mach-imx/src.c
> > @@ -178,9 +178,17 @@ void __init imx_src_init(void)
> >         WARN_ON(!src_base);
> > 
> >         imx_reset_controller.of_node = np;
> > -       if (IS_ENABLED(CONFIG_RESET_CONTROLLER))
> > +       if (IS_ENABLED(CONFIG_RESET_CONTROLLER)) {
> >                 reset_controller_register(&imx_reset_controller);
> > 
> > +               /*
> > +                * The reset-controller node is never associated with a struct
> > +                * device, which trips up fw_devlink=on. As a workaround, drop
> > +                * all devlinks to/from this node.
> > +                */
> > +               fw_devlink_purge_absent_suppliers(&np->fwnode);
> > +       }
> > +
> 
> Hey Philipp,
> 
> Can you point me to the .dts file that corresponds to this platform? I
> want to take a closer look.

Thank you, the relevant file is arch/arm/boot/dts/imx6qdl.dtsi, device
nodes labeled as &src and &ipu1. This is for example included by
arch/arm/boot/dts/imx6q-nitrogen6x.dts. There's a second &ipu2 added in
arch/arm/boot/dts/imx6qd.dtsi as well.

I'm also seeing a few "Fixing up cyclic dependency with ldb/120000.hdmi"
messages, presumably due to the various of_graph links between ipu_di
and hdmi/ldb ports.

regards
Philipp