[PATCH 2/2] drm/amd/display: Add aux_backlight module option

[Takashi Iwai]

On Fri, 05 Feb 2021 17:34:36 +0100,
Alex Deucher wrote:
> 
> On Wed, Feb 3, 2021 at 7:42 AM Takashi Iwai <tiwai at suse.de> wrote:
> >
> > There seem devices that don't work with the aux channel backlight
> > control.  For allowing such users to test with the other backlight
> > control method, provide a new module option, aux_backlight, to specify
> > enabling or disabling the aux backport support explicitly.  As
> > default, the aux support is detected by the hardware capability.
> >
> > BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1180749
> > BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1438
> > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/amdgpu.h               | 1 +
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c           | 4 ++++
> >  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++
> >  3 files changed, 8 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > index 5993dd0fdd8e..4793cd5e69f9 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> > @@ -179,6 +179,7 @@ extern uint amdgpu_smu_memory_pool_size;
> >  extern uint amdgpu_dc_feature_mask;
> >  extern uint amdgpu_dc_debug_mask;
> >  extern uint amdgpu_dm_abm_level;
> > +extern int amdgpu_aux_backlight;
> >  extern struct amdgpu_mgpu_info mgpu_info;
> >  extern int amdgpu_ras_enable;
> >  extern uint amdgpu_ras_mask;
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > index 7169fb5e3d9c..5b66822da954 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > @@ -777,6 +777,10 @@ uint amdgpu_dm_abm_level;
> >  MODULE_PARM_DESC(abmlevel, "ABM level (0 = off (default), 1-4 = backlight reduction level) ");
> >  module_param_named(abmlevel, amdgpu_dm_abm_level, uint, 0444);
> >
> > +int amdgpu_aux_backlight = -1;
> > +MODULE_PARM_DESC(aux_backlight, "Aux backlight control (0 = off, 1 = on, default auto)");
> > +module_param_named(aux_backlight, amdgpu_aux_backlight, bint, 0444);
> 
> I'd suggest making this something more generic like "backlight" and
> make -1 auto, 0 pwm, 1 aux.  That way we can handle potential future
> types more cleanly.

OK, will respin later.


thanks,

Takashi