Skip to content

Commit

Permalink
drm/dp_mst: Add DSC enablement helpers to DRM
Browse files Browse the repository at this point in the history
Adding a helper function to be called by
drivers outside of DRM to enable DSC on
the MST ports.

Function is called to recalculate VCPI allocation
if DSC is enabled and raise the DSC flag to enable.
In case of disabling DSC the flag is set to false
and recalculation of VCPI slots is expected to be done
in encoder's atomic_check.

v2: squash separate functions into one and call it per
port
v3: Fix comment typos

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
  • Loading branch information
Mikita Lipski authored and Alex Deucher committed Jan 9, 2020
1 parent 1c6c1cb commit 8afb7e6
Show file tree
Hide file tree
Showing 2 changed files with 66 additions and 0 deletions.
61 changes: 61 additions & 0 deletions drivers/gpu/drm/drm_dp_mst_topology.c
Original file line number Diff line number Diff line change
Expand Up @@ -4789,6 +4789,67 @@ drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
return 0;
}

/**
* drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
* @state: Pointer to the new drm_atomic_state
* @port: Pointer to the affected MST Port
* @pbn: Newly recalculated bw required for link with DSC enabled
* @pbn_div: Divider to calculate correct number of pbn per slot
* @enable: Boolean flag to enable or disable DSC on the port
*
* This function enables DSC on the given Port
* by recalculating its vcpi from pbn provided
* and sets dsc_enable flag to keep track of which
* ports have DSC enabled
*
*/
int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
struct drm_dp_mst_port *port,
int pbn, int pbn_div,
bool enable)
{
struct drm_dp_mst_topology_state *mst_state;
struct drm_dp_vcpi_allocation *pos;
bool found = false;
int vcpi = 0;

mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);

if (IS_ERR(mst_state))
return PTR_ERR(mst_state);

list_for_each_entry(pos, &mst_state->vcpis, next) {
if (pos->port == port) {
found = true;
break;
}
}

if (!found) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
port, mst_state);
return -EINVAL;
}

if (pos->dsc_enabled == enable) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
port, enable, pos->vcpi);
vcpi = pos->vcpi;
}

if (enable) {
vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
port, vcpi);
if (vcpi < 0)
return -EINVAL;
}

pos->dsc_enabled = enable;

return vcpi;
}
EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
/**
* drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
* atomic update is valid
Expand Down
5 changes: 5 additions & 0 deletions include/drm/drm_dp_mst_helper.h
Original file line number Diff line number Diff line change
Expand Up @@ -502,6 +502,7 @@ struct drm_dp_payload {
struct drm_dp_vcpi_allocation {
struct drm_dp_mst_port *port;
int vcpi;
bool dsc_enabled;
struct list_head next;
};

Expand Down Expand Up @@ -781,6 +782,10 @@ 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 pbn_div);
int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
struct drm_dp_mst_port *port,
int pbn, int pbn_div,
bool enable);
int __must_check
drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,
Expand Down

0 comments on commit 8afb7e6

Please sign in to comment.