[Intel-gfx] [PATCH v2 1/6] drm: Include the encoder itself in possible_clones

[Daniel Vetter]

On Fri, Feb 07, 2020 at 04:50:01PM +0200, Ville Syrjälä wrote:
> On Fri, Feb 07, 2020 at 03:28:35PM +0100, Thomas Zimmermann wrote:
> > Hi
> > 
> > Am 07.02.20 um 14:59 schrieb Ville Syrjala:
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > The docs say possible_clones should always include the encoder itself.
> > > Since most drivers don't want to deal with the complexities of cloning
> > > let's allow them to set possible_clones=0 and instead we'll fix that
> > > up in the core.
> > > 
> > > We can't put this special case into drm_encoder_init() because drivers
> > > will have to fill up possible_clones after adding all the relevant
> > > encoders. Otherwise they wouldn't know the proper encoder indexes to
> > > use. So we'll just do it just before registering the encoders.
> > > 
> > > TODO: Should we do something similar for possible_crtcs==0?
> > > 
> > > Cc: Thomas Zimmermann <tzimmermann at suse.de>
> > > Cc: Daniel Vetter <daniel at ffwll.ch>
> > > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > May this fixup function should warn iff possible_clones was set to non-0
> > by the driver, but the encoder itself is missing.
> 
> Yeah, I guess we could do that.

+1 on that, should catch some bugs at least.

Also can you pls fix up the kerneldoc for drm_encoder.possible_clones,
defacto this now means that 0 is a totally fine setting.
-Daniel

> 
> > In any case
> > 
> > Acked-by: Thomas Zimmermann <tzimmermann at suse.de>
> > 
> > > ---
> > >  drivers/gpu/drm/drm_encoder.c | 15 +++++++++++++++
> > >  1 file changed, 15 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
> > > index e555281f43d4..f761d9306028 100644
> > > --- a/drivers/gpu/drm/drm_encoder.c
> > > +++ b/drivers/gpu/drm/drm_encoder.c
> > > @@ -66,11 +66,26 @@ static const struct drm_prop_enum_list drm_encoder_enum_list[] = {
> > >  	{ DRM_MODE_ENCODER_DPI, "DPI" },
> > >  };
> > >  
> > > +/*
> > > + * For some reason we want the encoder itself included in
> > > + * possible_clones. Make life easy for drivers by allowing them
> > > + * to leave possible_clones unset if no cloning is possible.
> > > + */
> > > +static void fixup_possible_clones(struct drm_device *dev)
> > > +{
> > > +	struct drm_encoder *encoder;
> > > +
> > > +	drm_for_each_encoder(encoder, dev)
> > > +		encoder->possible_clones |= drm_encoder_mask(encoder);
> > > +}
> > > +
> > >  int drm_encoder_register_all(struct drm_device *dev)
> > >  {
> > >  	struct drm_encoder *encoder;
> > >  	int ret = 0;
> > >  
> > > +	fixup_possible_clones(dev);
> > > +
> > >  	drm_for_each_encoder(encoder, dev) {
> > >  		if (encoder->funcs->late_register)
> > >  			ret = encoder->funcs->late_register(encoder);
> > > 
> > 
> > -- 
> > Thomas Zimmermann
> > Graphics Driver Developer
> > SUSE Software Solutions Germany GmbH
> > Maxfeldstr. 5, 90409 Nürnberg, Germany
> > (HRB 36809, AG Nürnberg)
> > Geschäftsführer: Felix Imendörffer
> > 
> 
> 
> 
> 
> -- 
> Ville Syrjälä
> Intel
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch