Re: [PATCH v2] drm/dp: Move panel DP AUX backlight support to drm_dp_helper

[Doug Anderson]

Hi,

On Mon, Jul 12, 2021 at 8:02 AM Douglas Anderson <dianders@xxxxxxxxxxxx> wrote:
>
> We were getting a depmod error:
>   depmod: ERROR: Cycle detected: drm_kms_helper -> drm -> drm_kms_helper
>
> It looks like the rule is that drm_kms_helper can call into drm, but
> drm can't call into drm_kms_helper. That means we've got to move the
> DP AUX backlight support into drm_dp_helper.
>
> NOTE: as part of this, I didn't try to do any renames of the main
> registration function. Even though it's in the drm_dp_helper, it still
> feels very parallel to drm_panel_of_backlight().
>
> Fixes: 10f7b40e4f30 ("drm/panel: add basic DP AUX backlight support")
> Reported-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Reported-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> ---
> Note that I've compile tested this, but I don't have a device setup
> yet that uses this code. Since the code is basically the same as it
> was this should be OK, but if Rajeev could confirm that nothing is
> broken that'd be nice.
>
> Changes in v2:
> - Guard new functions by the proper configs.
>
>  drivers/gpu/drm/drm_dp_helper.c | 113 ++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_panel.c     | 108 ------------------------------
>  include/drm/drm_dp_helper.h     |  16 +++++
>  include/drm/drm_panel.h         |   8 ---
>  4 files changed, 129 insertions(+), 116 deletions(-)

Pushed to drm-misc-next with Rajeev's review:

072ed3431f5b drm/dp: Move panel DP AUX backlight support to drm_dp_helper

-Doug