Re: [Freedreno] [PATCH v9 3/5] drm/msm/dp: add support for DP PLL driver

[Tanmay Shah]

On 2020-08-11 13:21, Randy Dunlap wrote:
> On 8/11/20 12:49 PM, tanmay@xxxxxxxxxxxxxx wrote:
> > On 2020-08-07 13:28, Randy Dunlap wrote:
> > > On 8/7/20 1:24 PM, Stephen Boyd wrote:
> > > > Quoting Rob Clark (2020-08-07 08:51:48)
> > > > > On Fri, Aug 7, 2020 at 8:27 AM Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> > > > > wrote:
> > > > > > On 8/7/20 12:17 AM, Tanmay Shah wrote:
> > > > > > > diff --git a/drivers/gpu/drm/msm/Kconfig 
> > > > > > > b/drivers/gpu/drm/msm/Kconfig
> > > > > > > index ea3c4d094d09..cc1392b29022 100644
> > > > > > > --- a/drivers/gpu/drm/msm/Kconfig
> > > > > > > +++ b/drivers/gpu/drm/msm/Kconfig
> > > > > > > @@ -60,6 +60,7 @@ config DRM_MSM_HDMI_HDCP
> > > > > > >  config DRM_MSM_DP
> > > > > > >       bool "Enable DP support in MSM DRM driver"
> > > > > > >       depends on DRM_MSM
> > > > > > > +     default y
> > > > > > >       help
> > > > > > >         Compile in support for DP driver in msm drm driver. DP 
> > > > > > > external
> > > > > > >         display support is enabled through this config option. It 
> > > > > > > can
> > > > > >
> > > > > > Hi,
> > > > > >
> > > > > > You need a very strong justification to make an optional part of a
> > > > > > driver
> > > > > > to be "default y".
> > > > >
> > > > > My opinion is that if the driver is built, everything should be 
> > > > > built.
> > > > > This is what makes sense for distro's.  It is only the embedded 
> > > > > case
> > > > > where you want to trim down unneeded features where you might want 
> > > > > to
> > > > > disable some parts.  So 'default y' makes sense to me.
> > >
> > > We don't set defaults for distro convenience.
> > >
> > > > Maybe use 'default DRM_MSM' so that it doesn't trigger the 'default 
> > > > y'
> > > > filters people have?
> > >
> > > Most people can figure that one out.  ;)
> > > I don't have any automated filters.
> >
> > After after further reviews, I agree with Rob. Display Port is 
> > required module as of now so it makes sense to keep 'default y'.
>
> If it is required, then you don't need to have a Kconfig entry/symbol 
> for it.

Kconfig makes driver flexible. Other moudles in the driver are also 
'default y' such as DSI. I will let Rob guide us further on this as he 
is the maintainer.