Re: [PATCH 03/20] drm/amd/display: Introduce MAX_LINK_ENCODERS

["Timur Kristóf" <timur.kristof@gmail.com>]

On Tue, 2025-07-29 at 14:06 -0400, Harry Wentland wrote:
> 
> 
> On 2025-07-23 11:57, Timur Kristóf wrote:
> > We are going to support analog encoders as well, not just digital,
> > so we need to make space for them in various arrays.
> > 
> > Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
> > ---
> >  .../drm/amd/display/dc/core/dc_link_enc_cfg.c |  4 ++--
> >  .../gpu/drm/amd/display/dc/inc/core_types.h   |  8 +++----
> >  .../gpu/drm/amd/display/dc/inc/hw/hw_shared.h | 24
> > +++++++++++++++++++
> >  3 files changed, 30 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_enc_cfg.c
> > b/drivers/gpu/drm/amd/display/dc/core/dc_link_enc_cfg.c
> > index 814f68d76257..d86482611b3f 100644
> > --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_enc_cfg.c
> > +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_enc_cfg.c
> > @@ -522,10 +522,10 @@ struct link_encoder
> > *link_enc_cfg_get_link_enc_used_by_link(
> >  struct link_encoder *link_enc_cfg_get_next_avail_link_enc(struct
> > dc *dc)
> >  {
> >  	struct link_encoder *link_enc = NULL;
> > -	enum engine_id encs_assigned[MAX_DIG_LINK_ENCODERS];
> > +	enum engine_id encs_assigned[MAX_LINK_ENCODERS];
> >  	int i;
> >  
> > -	for (i = 0; i < MAX_DIG_LINK_ENCODERS; i++)
> > +	for (i = 0; i < MAX_LINK_ENCODERS; i++)
> >  		encs_assigned[i] = ENGINE_ID_UNKNOWN;
> >  
> >  	/* Add assigned encoders to list. */
> > diff --git a/drivers/gpu/drm/amd/display/dc/inc/core_types.h
> > b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
> > index f0d7185153b2..55daf348293e 100644
> > --- a/drivers/gpu/drm/amd/display/dc/inc/core_types.h
> > +++ b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
> > @@ -274,7 +274,7 @@ struct resource_pool {
> >  	/* An array for accessing the link encoder objects that
> > have been created.
> >  	 * Index in array corresponds to engine ID - viz. 0:
> > ENGINE_ID_DIGA
> >  	 */
> > -	struct link_encoder *link_encoders[MAX_DIG_LINK_ENCODERS];
> > +	struct link_encoder *link_encoders[MAX_LINK_ENCODERS];
> >  	/* Number of DIG link encoder objects created - i.e.
> > number of valid
> >  	 * entries in link_encoders array.
> >  	 */
> > @@ -508,7 +508,7 @@ struct pipe_ctx {
> >  struct link_enc_cfg_context {
> >  	enum link_enc_cfg_mode mode;
> >  	struct link_enc_assignment
> > link_enc_assignments[MAX_PIPES];
> > -	enum engine_id link_enc_avail[MAX_DIG_LINK_ENCODERS];
> > +	enum engine_id link_enc_avail[MAX_LINK_ENCODERS];
> >  	struct link_enc_assignment
> > transient_assignments[MAX_PIPES];
> >  };
> >  
> > @@ -520,8 +520,8 @@ struct resource_context {
> >  	uint8_t dp_clock_source_ref_count;
> >  	bool is_dsc_acquired[MAX_PIPES];
> >  	struct link_enc_cfg_context link_enc_cfg_ctx;
> > -	unsigned int
> > dio_link_enc_to_link_idx[MAX_DIG_LINK_ENCODERS];
> > -	int dio_link_enc_ref_cnts[MAX_DIG_LINK_ENCODERS];
> > +	unsigned int dio_link_enc_to_link_idx[MAX_LINK_ENCODERS];
> > +	int dio_link_enc_ref_cnts[MAX_LINK_ENCODERS];
> >  	bool is_hpo_dp_stream_enc_acquired[MAX_HPO_DP2_ENCODERS];
> >  	unsigned int
> > hpo_dp_link_enc_to_link_idx[MAX_HPO_DP2_LINK_ENCODERS];
> >  	int hpo_dp_link_enc_ref_cnts[MAX_HPO_DP2_LINK_ENCODERS];
> > diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h
> > b/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h
> > index 41c76ba9ba56..dc9b9f22c75b 100644
> > --- a/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h
> > +++ b/drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h
> > @@ -45,7 +45,31 @@
> >  #define MAX_PIPES 6
> >  #define MAX_PHANTOM_PIPES (MAX_PIPES / 2)
> >  #define MAX_LINKS (MAX_PIPES * 2 +2)
> > +
> > +/**
> > + * define MAX_DIG_LINK_ENCODERS - maximum number of digital
> > encoders
> > + *
> > + * Digital encoders are ENGINE_ID_DIGA...G, there are at most 7,
> > + * although not every GPU may have that many.
> > + */
> >  #define MAX_DIG_LINK_ENCODERS 7
> > +
> > +/**
> > + * define MAX_DIG_LINK_ENCODERS - maximum number of analog link
> > encoders
> 
> _DAC_, not _DIG_
> 
> Harry

That's a typo, will fix.

Timur.

> 
> > + *
> > + * Analog encoders are ENGINE_ID_DACA/B, there are at most 2,
> > + * although not every GPU may have that many. Modern GPUs
> > typically
> > + * don't have analog encoders.
> > + */
> > +#define MAX_DAC_LINK_ENCODERS 2
> > +
> > +/**
> > + * define MAX_LINK_ENCODERS - maximum number link encoders in
> > total
> > + *
> > + * This includes both analog and digital encoders.
> > + */
> > +#define MAX_LINK_ENCODERS (MAX_DIG_LINK_ENCODERS +
> > MAX_DAC_LINK_ENCODERS)
> > +
> >  #define MAX_DWB_PIPES	1
> >  #define MAX_HPO_DP2_ENCODERS	4
> >  #define MAX_HPO_DP2_LINK_ENCODERS	4