[PATCH AUTOSEL 6.11 08/15] drm: display: Set fwnode for aux bus devices

[Saravana Kannan]

On Thu, Dec 5, 2024 at 4:06 PM Saravana Kannan <saravanak at google.com> wrote:
>
> On Wed, Dec 4, 2024 at 3:29 PM Sasha Levin <sashal at kernel.org> wrote:
> >
> > From: Saravana Kannan <saravanak at google.com>
> >
> > [ Upstream commit fe2e59aa5d7077c5c564d55b7e2997e83710c314 ]
> >
> > fwnode needs to be set for a device for fw_devlink to be able to
> > track/enforce its dependencies correctly. Without this, you'll see error
> > messages like this when the supplier has probed and tries to make sure
> > all its fwnode consumers are linked to it using device links:
> >
> > mediatek-drm-dp 1c500000.edp-tx: Failed to create device link (0x180) with backlight-lcd0
> >
> > Reported-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
> > Closes: https://lore.kernel.org/all/7b995947-4540-4b17-872e-e107adca4598@notapiano/
> > Tested-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
> > Signed-off-by: Saravana Kannan <saravanak at google.com>
> > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> > Reviewed-by: Thierry Reding <treding at nvidia.com>
> > Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
> > Link: https://lore.kernel.org/r/20241024061347.1771063-2-saravanak@google.com
> > Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> > Signed-off-by: Sasha Levin <sashal at kernel.org>
>
> As mentioned in the original cover letter:
>
> PSA: Do not pull any of these patches into stable kernels. fw_devlink
> had a lot of changes that landed in the last year. It's hard to ensure
> cherry-picks have picked up all the dependencies correctly. If any of
> these really need to get cherry-picked into stable kernels, cc me and
> wait for my explicit Ack.
>
> Is there a pressing need for this in 4.19?

I copy pasted this into several replies. In all those cases I meant
the kernel version mentioned in the subject.

-Saravana

>
> -Saravana
>
> > ---
> >  drivers/gpu/drm/display/drm_dp_aux_bus.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/display/drm_dp_aux_bus.c b/drivers/gpu/drm/display/drm_dp_aux_bus.c
> > index d810529ebfb6e..ec7eac6b595f7 100644
> > --- a/drivers/gpu/drm/display/drm_dp_aux_bus.c
> > +++ b/drivers/gpu/drm/display/drm_dp_aux_bus.c
> > @@ -292,7 +292,7 @@ int of_dp_aux_populate_bus(struct drm_dp_aux *aux,
> >         aux_ep->dev.parent = aux->dev;
> >         aux_ep->dev.bus = &dp_aux_bus_type;
> >         aux_ep->dev.type = &dp_aux_device_type_type;
> > -       aux_ep->dev.of_node = of_node_get(np);
> > +       device_set_node(&aux_ep->dev, of_fwnode_handle(of_node_get(np)));
> >         dev_set_name(&aux_ep->dev, "aux-%s", dev_name(aux->dev));
> >
> >         ret = device_register(&aux_ep->dev);
> > --
> > 2.43.0
> >