Amend drm_dp_read_mst_cap() to return an enum, indicating "none",
"sideband messaging", or "mst". Modify all call sites to take the new
return value into account.
Cc: Arun R Murthy <arun.r.murthy@xxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
drivers/gpu/drm/display/drm_dp_mst_topology.c | 20 ++++++++++------
drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
drivers/gpu/drm/nouveau/nouveau_dp.c | 2 +-
include/drm/display/drm_dp_mst_helper.h | 23 ++++++++++++++++++-
4 files changed, 38 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index f7c6b60629c2..a68a6c8a2495 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -3603,24 +3603,30 @@ fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
EXPORT_SYMBOL(drm_dp_get_vc_payload_bw);
/**
- * drm_dp_read_mst_cap() - check whether or not a sink supports MST
+ * drm_dp_read_mst_cap() - Read the sink's MST mode capability
* @aux: The DP AUX channel to use
* @dpcd: A cached copy of the DPCD capabilities for this sink
*
- * Returns: %True if the sink supports MST, %false otherwise
+ * Returns: enum drm_dp_mst_mode to indicate MST mode capability
*/
-bool drm_dp_read_mst_cap(struct drm_dp_aux *aux,
- const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+enum drm_dp_mst_mode drm_dp_read_mst_cap(struct drm_dp_aux *aux,
+ const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
u8 mstm_cap;
if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
- return false;
+ return DP_MST_NONE;
if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
- return false;
+ return DP_MST_NONE;
+
+ if (mstm_cap & DP_MST_CAP)
+ return DP_MST_CAPABLE;
+
+ if (mstm_cap & DP_SINGLE_STREAM_SIDEBAND_MSG)
+ return DP_MST_SIDEBAND_MSG;
- return mstm_cap & DP_MST_CAP;
+ return DP_MST_NONE;
}
EXPORT_SYMBOL(drm_dp_read_mst_cap);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index ab415f41924d..7af09f2c008d 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4011,7 +4011,7 @@ intel_dp_can_mst(struct intel_dp *intel_dp)
return i915->display.params.enable_dp_mst &&
intel_dp_mst_source_support(intel_dp) &&
- drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd);
+ drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DP_MST_CAPABLE;
}
static void
@@ -4020,7 +4020,7 @@ intel_dp_configure_mst(struct intel_dp *intel_dp)
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
struct intel_encoder *encoder =
&dp_to_dig_port(intel_dp)->base;
- bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd);
+ bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd) == DP_MST_CAPABLE;
drm_dbg_kms(&i915->drm,
"[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s\n",
diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index 7de7707ec6a8..d180d22dbab0 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -181,7 +181,7 @@ nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
if (nouveau_mst) {
mstm = outp->dp.mstm;
if (mstm)
- mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
+ mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd) == DP_MST_CAPABLE;
}
if (nouveau_dp_has_sink_count(connector, outp)) {
diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h
index 9b19d8bd520a..db48016b2aed 100644
--- a/include/drm/display/drm_dp_mst_helper.h
+++ b/include/drm/display/drm_dp_mst_helper.h
@@ -818,7 +818,28 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
-bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
+/**
+ * enum drm_dp_mst_mode - sink's MST mode capability
+ */
+enum drm_dp_mst_mode {
+ /**
+ * @DP_MST_NONE: The sink does not support MST nor single stream
+ * sideband messaging.
+ */
+ DP_MST_NONE,
+ /**
+ * @DP_MST_CAPABLE: Sink supports MST, more than one stream and single
+ * stream sideband messaging.
+ */
+ DP_MST_CAPABLE,
+ /**
+ * @DP_MST_SIDEBAND_MSG: Sink supports only one stream and single stream
+ * sideband messaging.
+ */
+ DP_MST_SIDEBAND_MSG,
+};
+
+enum drm_dp_mst_mode drm_dp_read_mst_cap(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr,
--
2.39.2
