8b/10b encoding format requires to reserve the first slot for
recording metadata. Real data transmission starts from the second slot,
with a total of available 63 slots available.
In 128b/132b encoding format, metadata is transmitted separately
in LLCP packet before MTP. Real data transmission starts from
the first slot, with a total of 64 slots available.
v2:
* Move total/start slots to mst_state, and copy it to mst_mgr in
atomic_check
v3:
* Only keep the slot info on the mst_state
* add a start_slot parameter to the payload function, to facilitate non
atomic drivers (this is a temporary workaround and should be removed when
we are moving out the non atomic driver helpers)
v4:
*fixed typo and formatting
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@xxxxxxx>
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
---
.../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 2 +-
drivers/gpu/drm/drm_dp_mst_topology.c | 38 ++++++++++++++++---
drivers/gpu/drm/i915/display/intel_dp_mst.c | 4 +-
drivers/gpu/drm/nouveau/dispnv50/disp.c | 2 +-
drivers/gpu/drm/radeon/radeon_dp_mst.c | 4 +-
include/drm/drm_dp_mst_helper.h | 5 ++-
6 files changed, 43 insertions(+), 12 deletions(-)
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 ff0f91c93ba4..6169488e2011 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
@@ -251,7 +251,7 @@ bool dm_helpers_dp_mst_write_payload_allocation_table(
}
/* It's OK for this to fail */
- drm_dp_update_payload_part1(mst_mgr);
+ drm_dp_update_payload_part1(mst_mgr, 1);
/* mst_mgr->->payloads are VC payload notify MST branch using DPCD or
* AUX message. The sequence is slot 1-63 allocated sequence for each
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 5ab3b3a46e89..82ee6791576c 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3353,6 +3353,10 @@ static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
/**
* drm_dp_update_payload_part1() - Execute payload update part 1
* @mgr: manager to use.
+ * @start_slot: this is the cur slot
+ *
+ * NOTE: start_slot is a temporary workaround for non-atomic drivers,
+ * this will be removed when non-atomic mst helpers are moved out of the helper
*
* This iterates over all proposed virtual channels, and tries to
* allocate space in the link for them. For 0->slots transitions,
@@ -3360,15 +3364,15 @@ static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
* transitions, this writes the updated VCPIs and removes the
* remote VC payloads.
*
- * after calling this the driver should generate ACT and payload
+ *after calling this the driver should generate ACT and payload
* packets.
*/
-int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
+int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr, int start_slot)
{
struct drm_dp_payload req_payload;
struct drm_dp_mst_port *port;
int i, j;
- int cur_slots = 1;
+ int cur_slots = start_slot;
bool skip;
mutex_lock(&mgr->payload_lock);
@@ -4503,6 +4507,27 @@ int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
}
EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
+/**
+ * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format
+ * @mst_state: mst_state to update
+ * @link_encoding_cap: the ecoding format on the link
+ */
+void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap)
+{
+ if (link_encoding_cap == DP_CAP_ANSI_128B132B) {
+ mst_state->total_avail_slots = 64;
+ mst_state->start_slot = 0;
+ } else {
+ mst_state->total_avail_slots = 63;
+ mst_state->start_slot = 1;
+ }
+
+ DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n",
+ (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b",
+ mst_state->mgr);
+}
+EXPORT_SYMBOL(drm_dp_mst_update_slots);
+
/**
* drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
* @mgr: manager for this port
@@ -5222,7 +5247,7 @@ drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_topology_state *mst_state)
{
struct drm_dp_vcpi_allocation *vcpi;
- int avail_slots = 63, payload_count = 0;
+ int avail_slots = mst_state->total_avail_slots, payload_count = 0;
list_for_each_entry(vcpi, &mst_state->vcpis, next) {
/* Releasing VCPI is always OK-even if the port is gone */
@@ -5251,7 +5276,7 @@ drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
}
}
drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
- mgr, mst_state, avail_slots, 63 - avail_slots);
+ mgr, mst_state, avail_slots, mst_state->total_avail_slots - avail_slots);
return 0;
}
@@ -5528,6 +5553,9 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
if (mst_state == NULL)
return -ENOMEM;
+ mst_state->total_avail_slots = 63;
+ mst_state->start_slot = 1;
+
mst_state->mgr = mgr;
INIT_LIST_HEAD(&mst_state->vcpis);
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index b170e272bdee..d3a24189a12c 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -368,7 +368,7 @@ static void intel_mst_disable_dp(struct intel_atomic_state *state,
drm_dp_mst_reset_vcpi_slots(&intel_dp->mst_mgr, connector->port);
- ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
+ ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr, 1);
if (ret) {
drm_dbg_kms(&i915->drm, "failed to update payload %d\n", ret);
}
@@ -516,7 +516,7 @@ static void intel_mst_pre_enable_dp(struct intel_atomic_state *state,
intel_dp->active_mst_links++;
- ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
+ ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr, 1);
/*
* Before Gen 12 this is not done as part of
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index f949767698fc..6c8c59c26dbf 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1413,7 +1413,7 @@ nv50_mstm_prepare(struct nv50_mstm *mstm)
int ret;
NV_ATOMIC(drm, "%s: mstm prepare\n", mstm->outp->base.base.name);
- ret = drm_dp_update_payload_part1(&mstm->mgr);
+ ret = drm_dp_update_payload_part1(&mstm->mgr, 1);
drm_for_each_encoder(encoder, mstm->outp->base.base.dev) {
if (encoder->encoder_type == DRM_MODE_ENCODER_DPMST) {
diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c
index ec867fa880a4..751c2c075e09 100644
--- a/drivers/gpu/drm/radeon/radeon_dp_mst.c
+++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c
@@ -423,7 +423,7 @@ radeon_mst_encoder_dpms(struct drm_encoder *encoder, int mode)
drm_dp_mst_allocate_vcpi(&radeon_connector->mst_port->mst_mgr,
radeon_connector->port,
mst_enc->pbn, slots);
- drm_dp_update_payload_part1(&radeon_connector->mst_port->mst_mgr);
+ drm_dp_update_payload_part1(&radeon_connector->mst_port->mst_mgr, 1);
radeon_dp_mst_set_be_cntl(primary, mst_enc,
radeon_connector->mst_port->hpd.hpd, true);
@@ -452,7 +452,7 @@ radeon_mst_encoder_dpms(struct drm_encoder *encoder, int mode)
return;
drm_dp_mst_reset_vcpi_slots(&radeon_connector->mst_port->mst_mgr, mst_enc->port);
- drm_dp_update_payload_part1(&radeon_connector->mst_port->mst_mgr);
+ drm_dp_update_payload_part1(&radeon_connector->mst_port->mst_mgr, 1);
drm_dp_check_act_status(&radeon_connector->mst_port->mst_mgr);
/* and this can also fail */
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index ddb9231d0309..78044ac5b59b 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -554,6 +554,8 @@ struct drm_dp_mst_topology_state {
struct drm_private_state base;
struct list_head vcpis;
struct drm_dp_mst_topology_mgr *mgr;
+ u8 total_avail_slots;
+ u8 start_slot;
};
#define to_dp_mst_topology_mgr(x) container_of(x, struct drm_dp_mst_topology_mgr, base)
@@ -806,6 +808,7 @@ int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp
void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
+void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap);
void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port);
@@ -815,7 +818,7 @@ int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
int pbn);
-int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr);
+int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr, int start_slot);
int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr);
--
2.25.1
