# Re: \[v8 1/6\] drm/panel: add basic DP AUX backlight support

- From: Doug Anderson \<dianders@chromium.org\>
- Date: 2021-07-12 13:46:01 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2021/07/1441968
- Thread: https://ratatoskr.run/dri-devel/2021/06/1426702/t.md

```text
Hi,

On Mon, Jul 12, 2021 at 2:41 AM Thomas Zimmermann [ref] wrote:
>
> > +     ret = drm_dp_dpcd_read(aux, DP_EDP_DPCD_REV, edp_dpcd,
> > +                            EDP_DISPLAY_CTL_CAP_SIZE);
>
> This creates a cyclic dependency between drm_kms_helper-ko and drm.ko.
> drm_panel.c is in the latter, while drm_dp_dpcd_read() in
> drm_dp_helper.c is in the former. Please fix.

Yeah, this was reported Friday and I posted a patch to try to fix it:

https://lore.kernel.org/lkml/20210709152909.1.I23eb4cc5a680341e7b3e791632a635566fa5806a@changeid/

I see Rajeev had some feedback on it. Once I've dug out of my weekend
email hole I'll take a look at plan to post a v2 ASAP.

-Doug
```