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

[Harry Wentland]

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 at 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

> + *
> + * 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