[PATCH v4 2/2] drm/panel: Add device_link from panel device to drm device

[Linus Walleij]

On Thu, Aug 30, 2018 at 4:41 PM Andrzej Hajda <a.hajda at samsung.com> wrote:
> [Me]
> > This happens because the connector struct device is the
> > same as the bridge struct device, I suppose.
>
> I guess it is rather because the code tries to make circular dependency:
> 1. panel depends on dsi-host because it is MIPI-DSI child device.
> 2. dsi-host probably depends on drm parent device (connector->dev->dev)
> - what drm driver do you use?

The driver is added in this patch, it's at this uncomfortable stage
where I have to make a big upfront design for a new DRM driver
and everything is shaky and unreviewed.

So to get it out for proper review it needs to be working and to
get it working I need review :D DRM development catch 22.

But here is the patch adding it all, in some in-flight state:
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson.git/commit/?h=ux500-mcde

Thanks a lot for these notes, I hope I can figure it out!

> 3. drm parent dev depends on panel: this patch adds this dependency.
>
> If 2nd point is true it becomes circular dependency, but please verify it.

I tried to not make the DRM parent dev depend on the panel.

AFAICT (1) is true, (2) is true but not (3).

Yours,
Linus Walleij