From 1cd0a5ea427931016c3e95b20dc20f17604937cc Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Tue, 24 Oct 2023 04:08:59 +0300 Subject: drm/dp_mst: Factor out a helper to check the atomic state of a topology manager Factor out a helper to check the atomic state for one MST topology manager, returning the MST port where the BW limit check has failed. This will be used in a follow-up patch by the i915 driver to improve the BW sharing between MST streams. Cc: Lyude Paul Cc: dri-devel@lists.freedesktop.org Reviewed-by: Lyude Paul Acked-by: Maxime Ripard Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-5-imre.deak@intel.com --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 93 +++++++++++++++++++++------ 1 file changed, 74 insertions(+), 19 deletions(-) (limited to 'drivers/gpu/drm/display') diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index fa0049572f22..0fbfdd23ef4e 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -5180,11 +5180,13 @@ EXPORT_SYMBOL(drm_dp_mst_port_downstream_of_parent); static int drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, - struct drm_dp_mst_topology_state *state); + struct drm_dp_mst_topology_state *state, + struct drm_dp_mst_port **failing_port); static int drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, - struct drm_dp_mst_topology_state *state) + struct drm_dp_mst_topology_state *state, + struct drm_dp_mst_port **failing_port) { struct drm_dp_mst_atomic_payload *payload; struct drm_dp_mst_port *port; @@ -5213,7 +5215,7 @@ drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb); list_for_each_entry(port, &mstb->ports, next) { - ret = drm_dp_mst_atomic_check_port_bw_limit(port, state); + ret = drm_dp_mst_atomic_check_port_bw_limit(port, state, failing_port); if (ret < 0) return ret; @@ -5225,7 +5227,8 @@ drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, static int drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, - struct drm_dp_mst_topology_state *state) + struct drm_dp_mst_topology_state *state, + struct drm_dp_mst_port **failing_port) { struct drm_dp_mst_atomic_payload *payload; int pbn_used = 0; @@ -5246,13 +5249,15 @@ drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", port->parent, port); + *failing_port = port; return -EINVAL; } pbn_used = payload->pbn; } else { pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, - state); + state, + failing_port); if (pbn_used <= 0) return pbn_used; } @@ -5261,6 +5266,7 @@ drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", port->parent, port, pbn_used, port->full_pbn); + *failing_port = port; return -ENOSPC; } @@ -5438,20 +5444,79 @@ int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, } EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); +/** + * drm_dp_mst_atomic_check_mgr - Check the atomic state of an MST topology manager + * @state: The global atomic state + * @mgr: Manager to check + * @mst_state: The MST atomic state for @mgr + * @failing_port: Returns the port with a BW limitation + * + * Checks the given MST manager's topology state for an atomic update to ensure + * that it's valid. This includes checking whether there's enough bandwidth to + * support the new timeslot allocations in the atomic update. + * + * Any atomic drivers supporting DP MST must make sure to call this or + * the drm_dp_mst_atomic_check() function after checking the rest of their state + * in their &drm_mode_config_funcs.atomic_check() callback. + * + * See also: + * drm_dp_mst_atomic_check() + * drm_dp_atomic_find_time_slots() + * drm_dp_atomic_release_time_slots() + * + * Returns: + * - 0 if the new state is valid + * - %-ENOSPC, if the new state is invalid, because of BW limitation + * @failing_port is set to: + * - The non-root port where a BW limit check failed + * The returned port pointer is valid until at least + * one payload downstream of it exists. + * - %NULL if the BW limit check failed at the root port + * - %-EINVAL, if the new state is invalid, because the root port has + * too many payloads. + */ +int drm_dp_mst_atomic_check_mgr(struct drm_atomic_state *state, + struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_topology_state *mst_state, + struct drm_dp_mst_port **failing_port) +{ + int ret; + + *failing_port = NULL; + + if (!mgr->mst_state) + return 0; + + ret = drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); + if (ret) + return ret; + + mutex_lock(&mgr->lock); + ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, + mst_state, + failing_port); + mutex_unlock(&mgr->lock); + + return ret < 0 ? ret : 0; +} +EXPORT_SYMBOL(drm_dp_mst_atomic_check_mgr); + /** * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an * atomic update is valid * @state: Pointer to the new &struct drm_dp_mst_topology_state * * Checks the given topology state for an atomic update to ensure that it's - * valid. This includes checking whether there's enough bandwidth to support - * the new timeslot allocations in the atomic update. + * valid, calling drm_dp_mst_atomic_check_mgr() for all MST manager in the + * atomic state. This includes checking whether there's enough bandwidth to + * support the new timeslot allocations in the atomic update. * * Any atomic drivers supporting DP MST must make sure to call this after * checking the rest of their state in their * &drm_mode_config_funcs.atomic_check() callback. * * See also: + * drm_dp_mst_atomic_check_mgr() * drm_dp_atomic_find_time_slots() * drm_dp_atomic_release_time_slots() * @@ -5466,21 +5531,11 @@ int drm_dp_mst_atomic_check(struct drm_atomic_state *state) int i, ret = 0; for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { - if (!mgr->mst_state) - continue; + struct drm_dp_mst_port *tmp_port; - ret = drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); + ret = drm_dp_mst_atomic_check_mgr(state, mgr, mst_state, &tmp_port); if (ret) break; - - mutex_lock(&mgr->lock); - ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, - mst_state); - mutex_unlock(&mgr->lock); - if (ret < 0) - break; - else - ret = 0; } return ret; -- cgit v1.2.3