On Thu, 2017-03-30 at 01:42 -0700, Dhinakaran Pandiyan wrote:
From: "Pandiyan, Dhinakaran" dhinakaran.pandiyan@intel.com
drm_dp_atomic_find_vcpi_slots() should be called from ->atomic_check() to check there are sufficient vcpi slots for a mode and to add that to the state. This should be followed by a call to drm_dp_mst_allocate_vcpi() in ->atomic_commit() to initialize a struct vcpi for the port.
drm_dp_atomic_release_vcpi_slots() should be called from ->atomic_check() to release a port's vcpi slot allocation from the state.
Drivers that do not make use of this atomic helper are expected to call drm_dp_find_vcpi_slots() instead before calling drm_dp_mst_allocate_vcpi().
v2: Added checks for verifying the port reference is valid Moved get_mst_topology_state() into the helpers (Daniel) Changed find_vcpi_slots() to not depend on current allocation
Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Archit Taneja architt@codeaurora.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Harry Wentland Harry.wentland@amd.com Reviewed-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com Signed-off-by: Dhinakaran Pandiyan dhinakaran.pandiyan@intel.com
drivers/gpu/drm/drm_dp_mst_topology.c | 75 +++++++++++++++++++++++++++++++++++ include/drm/drm_dp_mst_helper.h | 6 +++ 2 files changed, 81 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 0ad0baa..9f3954e 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2498,6 +2498,81 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, }
/**
- drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state
- @state: global atomic state
- @mgr: MST topology manager for the port
- @port: port to find vcpi slots for
- @pbn: bandwidth required for the mode in PBN
- RETURNS:
- Total slots in the atomic state assigned for this port or error
- */
+int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,struct drm_dp_mst_port *port, int pbn)+{
- struct drm_dp_mst_topology_state *topology_state;
- int req_slots;
- topology_state = drm_atomic_get_mst_topology_state(state, mgr);
- if (topology_state == NULL)
return -ENOMEM;- port = drm_dp_get_validated_port_ref(mgr, port);
- if (port == NULL)
return -EINVAL;- req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
- DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n",
req_slots, topology_state->avail_slots);- if (req_slots > topology_state->avail_slots) {
drm_dp_put_port(port);return -ENOSPC;- }
- topology_state->avail_slots -= req_slots;
- DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots);
- drm_dp_put_port(port);
- return req_slots;
+} +EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
+/**
- drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
- @state: global atomic state
- @mgr: MST topology manager for the port
- @port: port to release the vcpi slots for
- RETURNS:
- Number of slots released from the atomic state for this port
- */
+int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,struct drm_dp_mst_port *port)+{
- struct drm_dp_mst_topology_state *topology_state;
- int curr_slots;
- topology_state = drm_atomic_get_mst_topology_state(state, mgr);
- if (topology_state == NULL)
return -ENOMEM;- port = drm_dp_get_validated_port_ref(mgr, port);
- if (port == NULL)
return -EINVAL;- curr_slots = port->vcpi.num_slots;
This is a problem if the port has been destroyed.
- topology_state->avail_slots += curr_slots;
- DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n",
curr_slots, topology_state->avail_slots);- drm_dp_put_port(port);
- return curr_slots;
+}
Should we do this instead?
int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int slots) { struct drm_dp_mst_topology_state *topology_state;
topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (topology_state == NULL) return -ENOMEM;
/* We cannot rely on port->vcpi.num_slots to update * topology_state->avail_slots as the port may not exist if the parent * branch device was unplugged. This should be fixed by tracking * per-port slot allocation in drm_dp_mst_topology_state instead of * depending on the caller to tell us how many slots to release. */ topology_state->avail_slots += slots; DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n", slots, topology_state->avail_slots);
return 0; }
+EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
+/**
- drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
- @mgr: manager for this port
- @port: port to allocate a virtual channel for.
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h index 0b371df..64e7dac 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -615,5 +615,11 @@ void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr); int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr); struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr); +int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,struct drm_dp_mst_port *port, int pbn);+int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,struct drm_dp_mst_port *port);#endif