[PATCH v4 14/14] drm/amd/display: move dc_sink from dc_edid to drm_edid

Mario Limonciello mario.limonciello at amd.com
Fri Jun 13 18:26:51 UTC 2025


On 6/13/2025 9:58 AM, Melissa Wen wrote:
> Reduce direct handling of edid data by resorting to drm helpers that
> deal with this info inside drm_edid infrastructure.
> 
> v3:
> - use dc_edid_sink_edid_free in link_detection
> 
> Signed-off-by: Melissa Wen <mwen at igalia.com>
> ---
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 26 +++++++------------
>   .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 24 +++++------------
>   .../display/amdgpu_dm/amdgpu_dm_mst_types.c   | 21 +++++----------
>   .../gpu/drm/amd/display/amdgpu_dm/dc_edid.c   | 26 +++++++++----------
>   .../gpu/drm/amd/display/amdgpu_dm/dc_edid.h   |  1 +
>   .../drm/amd/display/dc/link/link_detection.c  |  3 ++-
>   6 files changed, 40 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index c7efeb9f38b6..ec33a6236e37 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -68,6 +68,7 @@
>   #endif
>   #include "amdgpu_dm_psr.h"
>   #include "amdgpu_dm_replay.h"
> +#include "dc_edid.h"
>   
>   #include "ivsrcid/ivsrcid_vislands30.h"
>   
> @@ -3708,6 +3709,8 @@ void amdgpu_dm_update_connector_after_detect(
>   	 * 2. Send an event and let userspace tell us what to do
>   	 */
>   	if (sink) {
> +		const struct drm_edid *drm_edid = sink->drm_edid;
> +
>   		/*
>   		 * TODO: check if we still need the S3 mode update workaround.
>   		 * If yes, put it here.
> @@ -3719,16 +3722,15 @@ void amdgpu_dm_update_connector_after_detect(
>   
>   		aconnector->dc_sink = sink;
>   		dc_sink_retain(aconnector->dc_sink);
> -		if (sink->dc_edid.length == 0) {
> +
> +		if (!drm_edid_valid(drm_edid)) {
>   			aconnector->drm_edid = NULL;
>   			hdmi_cec_unset_edid(aconnector);
>   			if (aconnector->dc_link->aux_mode) {
>   				drm_dp_cec_unset_edid(&aconnector->dm_dp_aux.aux);
>   			}
>   		} else {
> -			const struct edid *edid = (const struct edid *)sink->dc_edid.raw_edid;
> -
> -			aconnector->drm_edid = drm_edid_alloc(edid, sink->dc_edid.length);
> +			aconnector->drm_edid = drm_edid_dup(sink->drm_edid);
>   			drm_edid_connector_update(connector, aconnector->drm_edid);
>   
>   			hdmi_cec_set_edid(aconnector);
> @@ -7378,12 +7380,8 @@ static void amdgpu_dm_connector_funcs_force(struct drm_connector *connector)
>   	aconnector->drm_edid = drm_edid;
>   	/* Update emulated (virtual) sink's EDID */
>   	if (dc_em_sink && dc_link) {
> -		// FIXME: Get rid of drm_edid_raw()
> -		const struct edid *edid = drm_edid_raw(drm_edid);
> -
>   		memset(&dc_em_sink->edid_caps, 0, sizeof(struct dc_edid_caps));
> -		memmove(dc_em_sink->dc_edid.raw_edid, edid,
> -			(edid->extensions + 1) * EDID_LENGTH);
> +		dc_edid_copy_edid_to_dc(dc_em_sink, drm_edid, 0);
>   		dm_helpers_parse_edid_caps(dc_link, dc_em_sink);
>   	}
>   }
> @@ -7416,7 +7414,6 @@ static void create_eml_sink(struct amdgpu_dm_connector *aconnector)
>   			.sink_signal = SIGNAL_TYPE_VIRTUAL
>   	};
>   	const struct drm_edid *drm_edid;
> -	const struct edid *edid;
>   	struct i2c_adapter *ddc;
>   
>   	if (dc_link && dc_link->aux_mode)
> @@ -7436,12 +7433,9 @@ static void create_eml_sink(struct amdgpu_dm_connector *aconnector)
>   
>   	aconnector->drm_edid = drm_edid;
>   
> -	edid = drm_edid_raw(drm_edid); // FIXME: Get rid of drm_edid_raw()
> -	aconnector->dc_em_sink = dc_link_add_remote_sink(
> -		aconnector->dc_link,
> -		(uint8_t *)edid,
> -		(edid->extensions + 1) * EDID_LENGTH,
> -		&init_params);
> +	aconnector->dc_em_sink = dc_link_add_remote_sink(aconnector->dc_link,
> +							 drm_edid, 0,
> +							 &init_params);
>   
>   	if (aconnector->base.force == DRM_FORCE_ON) {
>   		aconnector->dc_sink = aconnector->dc_link->local_sink ?
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> index abfce44dcee7..3e9d04760c21 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> @@ -48,6 +48,7 @@
>   #include "dm_helpers.h"
>   #include "ddc_service_types.h"
>   #include "clk_mgr.h"
> +#include "dc_edid.h"
>   
>   static void apply_edid_quirks(struct drm_device *dev,
>   			      const struct drm_edid *drm_edid,
> @@ -100,20 +101,16 @@ enum dc_edid_status dm_helpers_parse_edid_caps(struct dc_link *link,
>   	struct amdgpu_dm_connector *aconnector = link->priv;
>   	struct drm_connector *connector = &aconnector->base;
>   	struct drm_device *dev = connector->dev;
> -	struct edid *edid_buf;
> -	const struct drm_edid *drm_edid;
> +	const struct drm_edid *drm_edid = sink->drm_edid;
>   	struct drm_edid_product_id product_id;
>   	struct dc_edid_caps *edid_caps = &sink->edid_caps;
>   	int sad_count;
>   	int i = 0;
>   	enum dc_edid_status result = EDID_OK;
>   
> -	edid_buf = (struct edid *) &sink->dc_edid.raw_edid;
> -	if (!edid_caps || !edid_buf)
> +	if (!edid_caps || !drm_edid)
>   		return EDID_BAD_INPUT;
>   
> -	drm_edid = drm_edid_alloc(edid_buf, EDID_LENGTH * (edid_buf->extensions + 1));
> -
>   	if (!drm_edid_valid(drm_edid))
>   		result = EDID_BAD_CHECKSUM;
>   
> @@ -135,10 +132,8 @@ enum dc_edid_status dm_helpers_parse_edid_caps(struct dc_link *link,
>   	apply_edid_quirks(dev, drm_edid, edid_caps);
>   
>   	sad_count = drm_eld_sad_count(connector->eld);
> -	if (sad_count <= 0) {
> -		drm_edid_free(drm_edid);
> +	if (sad_count <= 0)
>   		return result;
> -	}
>   
>   	edid_caps->audio_mode_count = min(sad_count, DC_MAX_AUDIO_DESC_COUNT);
>   	for (i = 0; i < edid_caps->audio_mode_count; ++i) {
> @@ -158,8 +153,6 @@ enum dc_edid_status dm_helpers_parse_edid_caps(struct dc_link *link,
>   	else
>   		edid_caps->speaker_flags = DEFAULT_SPEAKER_LOCATION;
>   
> -	drm_edid_free(drm_edid);
> -
>   	return result;
>   }
>   
> @@ -991,7 +984,6 @@ enum dc_edid_status dm_helpers_read_local_edid(
>   	int retry = 3;
>   	enum dc_edid_status edid_status;
>   	const struct drm_edid *drm_edid;
> -	const struct edid *edid;
>   
>   	if (link->aux_mode)
>   		ddc = &aconnector->dm_dp_aux.aux.ddc;
> @@ -1021,11 +1013,7 @@ enum dc_edid_status dm_helpers_read_local_edid(
>   		if (!drm_edid)
>   			return EDID_NO_RESPONSE;
>   
> -		edid = drm_edid_raw(drm_edid); // FIXME: Get rid of drm_edid_raw()
> -		sink->dc_edid.length = EDID_LENGTH * (edid->extensions + 1);
> -		memmove(sink->dc_edid.raw_edid, (uint8_t *)edid, sink->dc_edid.length);
> -
> -		/* We don't need the original edid anymore */
> +		sink->drm_edid = drm_edid_dup(drm_edid);
>   		drm_edid_free(drm_edid);

Is the duplication actually necessary?  Can you "steal" the pointer by 
just assigning directly?

>   
>   		edid_status = dm_helpers_parse_edid_caps(link, sink);
> @@ -1051,6 +1039,8 @@ enum dc_edid_status dm_helpers_read_local_edid(
>   
>   		test_response.bits.EDID_CHECKSUM_WRITE = 1;
>   
> +		// TODO: drm_edid doesn't have a helper for dp_write_dpcd yet
> +		dc_edid_copy_edid_to_sink(sink);
>   		dm_helpers_dp_write_dpcd(ctx,
>   					link,
>   					DP_TEST_EDID_CHECKSUM,
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> index 7187d5aedf0a..5ca3e668c8aa 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> @@ -359,12 +359,10 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector)
>   					.link = aconnector->dc_link,
>   					.sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST };
>   
> -				dc_sink = dc_link_add_remote_sink(
> -					aconnector->dc_link,
> -					NULL,
> -					0,
> -					&init_params);
> -
> +				dc_sink = dc_link_add_remote_sink(aconnector->dc_link,
> +								  NULL,
> +								  0,
> +								  &init_params);
>   				if (!dc_sink) {
>   					DRM_ERROR("Unable to add a remote sink\n");
>   					return 0;
> @@ -397,15 +395,10 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector)
>   		struct dc_sink_init_data init_params = {
>   				.link = aconnector->dc_link,
>   				.sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST };
> -		const struct edid *edid;
> -
> -		edid = drm_edid_raw(aconnector->drm_edid); // FIXME: Get rid of drm_edid_raw()
> -		dc_sink = dc_link_add_remote_sink(
> -			aconnector->dc_link,
> -			(uint8_t *)edid,
> -			(edid->extensions + 1) * EDID_LENGTH,
> -			&init_params);
>   
> +		dc_sink = dc_link_add_remote_sink(aconnector->dc_link,
> +						  aconnector->drm_edid, 0,
> +						  &init_params);
>   		if (!dc_sink) {
>   			DRM_ERROR("Unable to add a remote sink\n");
>   			return 0;
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.c b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.c
> index 9e86dc15557b..ce4a7f9e268a 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.c
> @@ -6,25 +6,25 @@
>   bool dc_edid_is_same_edid(struct dc_sink *prev_sink,
>   			  struct dc_sink *current_sink)
>   {
> -	struct dc_edid *old_edid = &prev_sink->dc_edid;
> -	struct dc_edid *new_edid = &current_sink->dc_edid;
> -
> -       if (old_edid->length != new_edid->length)
> -               return false;
> -
> -       if (new_edid->length == 0)
> -               return false;
> -
> -       return (memcmp(old_edid->raw_edid,
> -                      new_edid->raw_edid, new_edid->length) == 0);
> +	return drm_edid_eq(prev_sink->drm_edid, current_sink->drm_edid);
>   }
>   
>   void dc_edid_copy_edid_to_dc(struct dc_sink *dc_sink,
>   			     const void *edid,
>   			     int len)
>   {
> -	memmove(dc_sink->dc_edid.raw_edid, edid, len);
> -	dc_sink->dc_edid.length = len;
> +	dc_sink->drm_edid = drm_edid_dup((const struct drm_edid *) edid);
> +}
> +
> +void dc_edid_copy_edid_to_sink(struct dc_sink *sink)
> +{
> +	const struct edid *edid;
> +	uint32_t edid_length;
> +
> +	edid = drm_edid_raw(sink->drm_edid); // FIXME: Get rid of drm_edid_raw()
> +	edid_length = EDID_LENGTH * (edid->extensions + 1);
> +	memcpy(sink->dc_edid.raw_edid, (uint8_t *) edid, edid_length);
> +	sink->dc_edid.length = edid_length;
>   }
>   
>   void dc_edid_sink_edid_free(struct dc_sink *sink)
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.h b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.h
> index 2c76768be459..a95cc6ccc743 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/dc_edid.h
> @@ -9,6 +9,7 @@ bool dc_edid_is_same_edid(struct dc_sink *prev_sink,
>   			  struct dc_sink *current_sink);
>   void dc_edid_copy_edid_to_dc(struct dc_sink *dc_sink,
>   			     const void *edid, int len);
> +void dc_edid_copy_edid_to_sink(struct dc_sink *sink);
>   void dc_edid_sink_edid_free(struct dc_sink *sink);
>   
>   #endif /* __DC_EDID_H__ */
> diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
> index c28072f980cc..bddcfd8f02ba 100644
> --- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c
> +++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
> @@ -1133,6 +1133,7 @@ static bool detect_link_and_local_sink(struct dc_link *link,
>   			dp_trace_init(link);
>   
>   		/* Connectivity log: detection */
> +		dc_edid_copy_edid_to_sink(sink);
>   		for (i = 0; i < sink->dc_edid.length / DC_EDID_BLOCK_SIZE; i++) {
>   			CONN_DATA_DETECT(link,
>   					 &sink->dc_edid.raw_edid[i * DC_EDID_BLOCK_SIZE],
> @@ -1415,7 +1416,7 @@ struct dc_sink *link_add_remote_sink(
>   	 * parsing fails
>   	 */
>   	if (edid_status != EDID_OK && edid_status != EDID_PARTIAL_VALID) {
> -		dc_sink->dc_edid.length = 0;
> +		dc_edid_sink_edid_free(dc_sink);
>   		dm_error("Bad EDID, status%d!\n", edid_status);
>   	}
>   



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