Nouveau - May 2021 - [PATCH v2 0/1] drm/dp_mst: Use kHz as link rate units when settig source max link caps at init

Change log:
  v2:
  - Added 'Acked-by' to comment
  
  v1:
  - Initial

Nikola Cornij (1):
  drm/dp_mst: Use kHz as link rate units when settig source max link
    caps at init

 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c   | 4 ++--
 drivers/gpu/drm/drm_dp_mst_topology.c                     | 8 ++++----
 drivers/gpu/drm/i915/display/intel_dp_mst.c               | 4 ++--
 drivers/gpu/drm/nouveau/dispnv50/disp.c                   | 5 +++--
 drivers/gpu/drm/radeon/radeon_dp_mst.c                    | 2 +-
 include/drm/drm_dp_mst_helper.h                           | 8 ++++----
 6 files changed, 16 insertions(+), 15 deletions(-)

-- 
2.25.1

[why]
Link rate in kHz is what is eventually required to calculate the link
bandwidth, which makes kHz a more generic unit. This should also make
forward-compatibility with new DP standards easier.

[how]
- Replace 'link rate DPCD code' with 'link rate in kHz' when
used with
drm_dp_mst_topology_mgr_init()
- Add/remove related DPCD code conversion from/to kHz where applicable

Signed-off-by: Nikola Cornij <nikola.cornij at amd.com>
Acked-by: Jani Nikula <jani.nikula at intel.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c   | 4 ++--
 drivers/gpu/drm/drm_dp_mst_topology.c                     | 8 ++++----
 drivers/gpu/drm/i915/display/intel_dp_mst.c               | 4 ++--
 drivers/gpu/drm/nouveau/dispnv50/disp.c                   | 5 +++--
 drivers/gpu/drm/radeon/radeon_dp_mst.c                    | 2 +-
 include/drm/drm_dp_mst_helper.h                           | 8 ++++----
 6 files changed, 16 insertions(+), 15 deletions(-)

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 4a0c24ce5f7d..f78dd021f591 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
@@ -458,8 +458,8 @@ void amdgpu_dm_initialize_dp_connector(struct
amdgpu_display_manager *dm,
 		&aconnector->dm_dp_aux.aux,
 		16,
 		4,
-		(u8)max_link_enc_cap.lane_count,
-		(u8)max_link_enc_cap.link_rate,
+		max_link_enc_cap.lane_count,
+		drm_dp_bw_code_to_link_rate(max_link_enc_cap.link_rate),
 		aconnector->connector_id);
 
 	drm_connector_attach_dp_subconnector_property(&aconnector->base);
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
b/drivers/gpu/drm/drm_dp_mst_topology.c
index 54604633e65c..32b7f8983b94 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3722,9 +3722,9 @@ int drm_dp_mst_topology_mgr_set_mst(struct
drm_dp_mst_topology_mgr *mgr, bool ms
 		}
 
 		lane_count = min_t(int, mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
mgr->max_lane_count);
-		link_rate = min_t(int, mgr->dpcd[1], mgr->max_link_rate);
+		link_rate = min_t(int, drm_dp_bw_code_to_link_rate(mgr->dpcd[1]),
mgr->max_link_rate);
 		mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr,
-							drm_dp_bw_code_to_link_rate(link_rate),
+							link_rate,
 							lane_count);
 		if (mgr->pbn_div == 0) {
 			ret = -EINVAL;
@@ -5454,7 +5454,7 @@ EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
  * @max_payloads: maximum number of payloads this GPU can source
  * @max_lane_count: maximum number of lanes this GPU supports
- * @max_link_rate: maximum link rate this GPU supports, units as in DPCD
+ * @max_link_rate: maximum link rate per lane this GPU supports in kHz
  * @conn_base_id: the connector object ID the MST device is connected to.
  *
  * Return 0 for success, or negative error code on failure
@@ -5462,7 +5462,7 @@ EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
 				 struct drm_device *dev, struct drm_dp_aux *aux,
 				 int max_dpcd_transaction_bytes, int max_payloads,
-				 u8 max_lane_count, u8 max_link_rate,
+				 int max_lane_count, int max_link_rate,
 				 int conn_base_id)
 {
 	struct drm_dp_mst_topology_state *mst_state;
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index f608c0cb98f4..26f65445bc8a 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -960,8 +960,8 @@ intel_dp_mst_encoder_init(struct intel_digital_port
*dig_port, int conn_base_id)
 	intel_dp_create_fake_mst_encoders(dig_port);
 	ret = drm_dp_mst_topology_mgr_init(&intel_dp->mst_mgr,
&i915->drm,
 					   &intel_dp->aux, 16, 3,
-					   (u8)dig_port->max_lanes,
-					   drm_dp_link_rate_to_bw_code(max_source_rate),
+					   dig_port->max_lanes,
+					   max_source_rate,
 					   conn_base_id);
 	if (ret)
 		return ret;
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c
b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index c46d0374b6e6..f949767698fc 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1617,8 +1617,9 @@ nv50_mstm_new(struct nouveau_encoder *outp, struct
drm_dp_aux *aux, int aux_max,
 	mstm->mgr.cbs = &nv50_mstm;
 
 	ret = drm_dp_mst_topology_mgr_init(&mstm->mgr, dev, aux, aux_max,
-					   (u8)max_payloads, outp->dcb->dpconf.link_nr,
-					   (u8)outp->dcb->dpconf.link_bw, conn_base_id);
+					   max_payloads, outp->dcb->dpconf.link_nr,
+					   drm_dp_bw_code_to_link_rate(outp->dcb->dpconf.link_bw),
+					   conn_base_id);
 	if (ret)
 		return ret;
 
diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c
b/drivers/gpu/drm/radeon/radeon_dp_mst.c
index 13072c2a6502..ec867fa880a4 100644
--- a/drivers/gpu/drm/radeon/radeon_dp_mst.c
+++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c
@@ -642,7 +642,7 @@ radeon_dp_mst_init(struct radeon_connector
*radeon_connector)
 	radeon_connector->mst_mgr.cbs = &mst_cbs;
 	return drm_dp_mst_topology_mgr_init(&radeon_connector->mst_mgr, dev,
 					    &radeon_connector->ddc_bus->aux, 16, 6,
-					    4, (u8)max_link_rate,
+					    4, drm_dp_bw_code_to_link_rate(max_link_rate),
 					    radeon_connector->base.base.id);
 }
 
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index c87a829b6498..ddb9231d0309 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -596,11 +596,11 @@ struct drm_dp_mst_topology_mgr {
 	/**
 	 * @max_lane_count: maximum number of lanes the GPU can drive.
 	 */
-	u8 max_lane_count;
+	int max_lane_count;
 	/**
-	 * @max_link_rate: maximum link rate per lane GPU can output.
+	 * @max_link_rate: maximum link rate per lane GPU can output, in kHz.
 	 */
-	u8 max_link_rate;
+	int max_link_rate;
 	/**
 	 * @conn_base_id: DRM connector ID this mgr is connected to. Only used
 	 * to build the MST connector path value.
@@ -774,7 +774,7 @@ int drm_dp_mst_topology_mgr_init(struct
drm_dp_mst_topology_mgr *mgr,
 				 struct drm_device *dev, struct drm_dp_aux *aux,
 				 int max_dpcd_transaction_bytes,
 				 int max_payloads,
-				 u8 max_lane_count, u8 max_link_rate,
+				 int max_lane_count, int max_link_rate,
 				 int conn_base_id);
 
 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
-- 
2.25.1

Reviewed-by: Lyude Paul <lyude at redhat.com>

Will let this sit on the list for a few days to see if anyone's got any
objections and then I'll go ahead and push it

On Wed, 2021-05-12 at 17:00 -0400, Nikola Cornij wrote:
> [why]
> Link rate in kHz is what is eventually required to calculate the link
> bandwidth, which makes kHz a more generic unit. This should also make
> forward-compatibility with new DP standards easier.
> 
> [how]
> - Replace 'link rate DPCD code' with 'link rate in kHz'
when used with
> drm_dp_mst_topology_mgr_init()
> - Add/remove related DPCD code conversion from/to kHz where applicable
> 
> Signed-off-by: Nikola Cornij <nikola.cornij at amd.com>
> Acked-by: Jani Nikula <jani.nikula at intel.com>
> ---
> ?.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c?? | 4 ++--
> ?drivers/gpu/drm/drm_dp_mst_topology.c???????????????????? | 8 ++++----
> ?drivers/gpu/drm/i915/display/intel_dp_mst.c?????????????? | 4 ++--
> ?drivers/gpu/drm/nouveau/dispnv50/disp.c?????????????????? | 5 +++--
> ?drivers/gpu/drm/radeon/radeon_dp_mst.c??????????????????? | 2 +-
> ?include/drm/drm_dp_mst_helper.h?????????????????????????? | 8 ++++----
> ?6 files changed, 16 insertions(+), 15 deletions(-)
> 
> 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 4a0c24ce5f7d..f78dd021f591 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
> @@ -458,8 +458,8 @@ void amdgpu_dm_initialize_dp_connector(struct
> amdgpu_display_manager *dm,
> ????????????????&aconnector->dm_dp_aux.aux,
> ????????????????16,
> ????????????????4,
> -???????????????(u8)max_link_enc_cap.lane_count,
> -???????????????(u8)max_link_enc_cap.link_rate,
> +???????????????max_link_enc_cap.lane_count,
> +???????????????drm_dp_bw_code_to_link_rate(max_link_enc_cap.link_rate),
> ????????????????aconnector->connector_id);
> ?
>
????????drm_connector_attach_dp_subconnector_property(&aconnector->base);
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 54604633e65c..32b7f8983b94 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -3722,9 +3722,9 @@ int drm_dp_mst_topology_mgr_set_mst(struct
> drm_dp_mst_topology_mgr *mgr, bool ms
> ????????????????}
> ?
> ????????????????lane_count = min_t(int, mgr->dpcd[2] &
DP_MAX_LANE_COUNT_MASK,
> mgr->max_lane_count);
> -???????????????link_rate = min_t(int, mgr->dpcd[1],
mgr->max_link_rate);
> +???????????????link_rate = min_t(int, drm_dp_bw_code_to_link_rate(mgr-
> >dpcd[1]), mgr->max_link_rate);
> ????????????????mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr,
> -
>
???????????????????????????????????????????????????????drm_dp_bw_code_to_link_r
> ate(link_rate),
> +???????????????????????????????????????????????????????link_rate,
> ????????????????????????????????????????????????????????lane_count);
> ????????????????if (mgr->pbn_div == 0) {
> ????????????????????????ret = -EINVAL;
> @@ -5454,7 +5454,7 @@ EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
> ? * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
> ? * @max_payloads: maximum number of payloads this GPU can source
> ? * @max_lane_count: maximum number of lanes this GPU supports
> - * @max_link_rate: maximum link rate this GPU supports, units as in DPCD
> + * @max_link_rate: maximum link rate per lane this GPU supports in kHz
> ? * @conn_base_id: the connector object ID the MST device is connected to.
> ? *
> ? * Return 0 for success, or negative error code on failure
> @@ -5462,7 +5462,7 @@ EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
> ?int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
> ???????????????????????????????? struct drm_device *dev, struct drm_dp_aux
> *aux,
> ???????????????????????????????? int max_dpcd_transaction_bytes, int
> max_payloads,
> -??????????????????????????????? u8 max_lane_count, u8 max_link_rate,
> +??????????????????????????????? int max_lane_count, int max_link_rate,
> ???????????????????????????????? int conn_base_id)
> ?{
> ????????struct drm_dp_mst_topology_state *mst_state;
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index f608c0cb98f4..26f65445bc8a 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -960,8 +960,8 @@ intel_dp_mst_encoder_init(struct intel_digital_port
> *dig_port, int conn_base_id)
> ????????intel_dp_create_fake_mst_encoders(dig_port);
> ????????ret = drm_dp_mst_topology_mgr_init(&intel_dp->mst_mgr,
&i915->drm,
> ?????????????????????????????????????????? &intel_dp->aux, 16, 3,
> -????????????????????????????????????????? (u8)dig_port->max_lanes,
> -?????????????????????????????????????????
> drm_dp_link_rate_to_bw_code(max_source_rate),
> +????????????????????????????????????????? dig_port->max_lanes,
> +????????????????????????????????????????? max_source_rate,
> ?????????????????????????????????????????? conn_base_id);
> ????????if (ret)
> ????????????????return ret;
> diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c
> b/drivers/gpu/drm/nouveau/dispnv50/disp.c
> index c46d0374b6e6..f949767698fc 100644
> --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
> +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
> @@ -1617,8 +1617,9 @@ nv50_mstm_new(struct nouveau_encoder *outp, struct
> drm_dp_aux *aux, int aux_max,
> ????????mstm->mgr.cbs = &nv50_mstm;
> ?
> ????????ret = drm_dp_mst_topology_mgr_init(&mstm->mgr, dev, aux,
aux_max,
> -????????????????????????????????????????? (u8)max_payloads, outp->dcb-
> >dpconf.link_nr,
> -?????????????????????????????????????????
(u8)outp->dcb->dpconf.link_bw,
> conn_base_id);
> +????????????????????????????????????????? max_payloads, outp->dcb-
> >dpconf.link_nr,
> +?????????????????????????????????????????
drm_dp_bw_code_to_link_rate(outp-
> >dcb->dpconf.link_bw),
> +????????????????????????????????????????? conn_base_id);
> ????????if (ret)
> ????????????????return ret;
> ?
> diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c
> b/drivers/gpu/drm/radeon/radeon_dp_mst.c
> index 13072c2a6502..ec867fa880a4 100644
> --- a/drivers/gpu/drm/radeon/radeon_dp_mst.c
> +++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c
> @@ -642,7 +642,7 @@ radeon_dp_mst_init(struct radeon_connector
> *radeon_connector)
> ????????radeon_connector->mst_mgr.cbs = &mst_cbs;
> ????????return
drm_dp_mst_topology_mgr_init(&radeon_connector->mst_mgr, dev,
> ???????????????????????????????????????????
&radeon_connector->ddc_bus->aux,
> 16, 6,
> -?????????????????????????????????????????? 4, (u8)max_link_rate,
> +?????????????????????????????????????????? 4,
> drm_dp_bw_code_to_link_rate(max_link_rate),
> ???????????????????????????????????????????
radeon_connector->base.base.id);
> ?}
> ?
> diff --git a/include/drm/drm_dp_mst_helper.h
b/include/drm/drm_dp_mst_helper.h
> index c87a829b6498..ddb9231d0309 100644
> --- a/include/drm/drm_dp_mst_helper.h
> +++ b/include/drm/drm_dp_mst_helper.h
> @@ -596,11 +596,11 @@ struct drm_dp_mst_topology_mgr {
> ????????/**
> ???????? * @max_lane_count: maximum number of lanes the GPU can drive.
> ???????? */
> -???????u8 max_lane_count;
> +???????int max_lane_count;
> ????????/**
> -??????? * @max_link_rate: maximum link rate per lane GPU can output.
> +??????? * @max_link_rate: maximum link rate per lane GPU can output, in
kHz.
> ???????? */
> -???????u8 max_link_rate;
> +???????int max_link_rate;
> ????????/**
> ???????? * @conn_base_id: DRM connector ID this mgr is connected to. Only
used
> ???????? * to build the MST connector path value.
> @@ -774,7 +774,7 @@ int drm_dp_mst_topology_mgr_init(struct
> drm_dp_mst_topology_mgr *mgr,
> ???????????????????????????????? struct drm_device *dev, struct drm_dp_aux
> *aux,
> ???????????????????????????????? int max_dpcd_transaction_bytes,
> ???????????????????????????????? int max_payloads,
> -??????????????????????????????? u8 max_lane_count, u8 max_link_rate,
> +??????????????????????????????? int max_lane_count, int max_link_rate,
> ???????????????????????????????? int conn_base_id);
> ?
> ?void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
-- 
Sincerely,
   Lyude Paul (she/her)
   Software Engineer at Red Hat
   
Note: I deal with a lot of emails and have a lot of bugs on my plate. If
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