Re: [PATCH v2, 1/2] drm/mediatek: Fix gamma correction issue

[CK Hu]

Hi, Yongqiang:

On Fri, 2019-12-13 at 16:03 +0800, Yongqiang Niu wrote:
> On Fri, 2019-12-13 at 15:48 +0800, CK Hu wrote:
> > Hi, Yongqiang:
> > 
> > The title is too rough. Any bug of gamma would be this title. I would
> > like the title show explicitly what it does.
> > 
> > On Fri, 2019-12-13 at 15:28 +0800, Yongqiang Niu wrote:
> > > if there is no gamma function in the crtc
> > > display path, don't add gamma property
> > > for crtc
> > > 
> > > Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
> > > ---
> > >  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 10 ++++++++--
> > >  1 file changed, 8 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > > index ca4fc47..9a8e1d4 100644
> > > --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > > +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > > @@ -734,6 +734,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> > >  	int pipe = priv->num_pipes;
> > >  	int ret;
> > >  	int i;
> > > +	uint gamma_lut_size = 0;
> > >  
> > >  	if (!path)
> > >  		return 0;
> > > @@ -785,6 +786,9 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> > >  		}
> > >  
> > >  		mtk_crtc->ddp_comp[i] = comp;
> > > +
> > > +		if (comp->funcs->gamma_set)
> > > +			gamma_lut_size = MTK_LUT_SIZE;
> > >  	}
> > >  
> > >  	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
> > > @@ -805,8 +809,10 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> > >  				NULL, pipe);
> > >  	if (ret < 0)
> > >  		return ret;
> > > -	drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
> > > -	drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, false, MTK_LUT_SIZE);
> > > +
> > > +	if (gamma_lut_size)
> > > +		drm_mode_crtc_set_gamma_size(&mtk_crtc->base, gamma_lut_size);
> > > +	drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, false, gamma_lut_size);
> > 
> > If there is no gamma, shall we enable color management?
> > 
> > Regards,
> > CK
> 
> drm_crtc_enable_color_mgmt will check the gamma_lut_size parameter,
> if no gamma, gamma_lut_size will be 0, and gamma_lut_size will not attch
> gamma property for the crtc

OK, you're right. So

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

and what title would you like?
I could modify it when I apply this patch.

Regards,
CK

> > 
> > >  	priv->num_pipes++;
> > >  	mutex_init(&mtk_crtc->hw_lock);
> > >  
> > 
> > 
> 
>