drm/i915/dp_mst: Add intel_dp_mst_{inc, dec}_active_streams()

Add helpers to increment/decrement the active MST stream count, instead
of open-coding these.

In mst_stream_pre_enable(), the increment will happen earlier, this is
ok, since nothing depends on the counter between the two points.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://lore.kernel.org/r/20250404150310.1156696-3-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 325c2a0346553ee520767b7831afe587c9b2c1f4..8084e7e8cf1146848011ca368f2ebd42b2382e7e 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -105,6 +105,29 @@ static struct intel_dp *to_primary_dp(struct intel_encoder *encoder)
        return &dig_port->dp;
 }
 
+static bool intel_dp_mst_dec_active_streams(struct intel_dp *intel_dp)
+{
+       struct intel_display *display = to_intel_display(intel_dp);
+
+       drm_dbg_kms(display->drm, "active MST streams %d -> %d\n",
+                   intel_dp->mst.active_links, intel_dp->mst.active_links - 1);
+
+       if (drm_WARN_ON(display->drm, intel_dp->mst.active_links == 0))
+               return true;
+
+       return --intel_dp->mst.active_links == 0;
+}
+
+static bool intel_dp_mst_inc_active_streams(struct intel_dp *intel_dp)
+{
+       struct intel_display *display = to_intel_display(intel_dp);
+
+       drm_dbg_kms(display->drm, "active MST streams %d -> %d\n",
+                   intel_dp->mst.active_links, intel_dp->mst.active_links + 1);
+
+       return intel_dp->mst.active_links++ == 0;
+}
+
 static int intel_dp_mst_max_dpt_bpp(const struct intel_crtc_state *crtc_state,
                                    bool dsc)
 {
@@ -1000,9 +1023,6 @@ static void mst_stream_disable(struct intel_atomic_state *state,
                to_intel_connector(old_conn_state->connector);
        enum transcoder trans = old_crtc_state->cpu_transcoder;
 
-       drm_dbg_kms(display->drm, "active links %d\n",
-                   intel_dp->mst.active_links);
-
        if (intel_dp->mst.active_links == 1)
                intel_dp->link.active = false;
 
@@ -1037,8 +1057,8 @@ static void mst_stream_post_disable(struct intel_atomic_state *state,
        bool last_mst_stream;
        int i;
 
-       intel_dp->mst.active_links--;
-       last_mst_stream = intel_dp->mst.active_links == 0;
+       last_mst_stream = intel_dp_mst_dec_active_streams(intel_dp);
+
        drm_WARN_ON(display->drm, DISPLAY_VER(display) >= 12 && last_mst_stream &&
                    !intel_dp_mst_is_master_trans(old_crtc_state));
 
@@ -1109,8 +1129,6 @@ static void mst_stream_post_disable(struct intel_atomic_state *state,
                primary_encoder->post_disable(state, primary_encoder,
                                              old_crtc_state, NULL);
 
-       drm_dbg_kms(display->drm, "active links %d\n",
-                   intel_dp->mst.active_links);
 }
 
 static void mst_stream_post_pll_disable(struct intel_atomic_state *state,
@@ -1194,13 +1212,11 @@ static void mst_stream_pre_enable(struct intel_atomic_state *state,
         */
        connector->encoder = encoder;
        intel_mst->connector = connector;
-       first_mst_stream = intel_dp->mst.active_links == 0;
+
+       first_mst_stream = intel_dp_mst_inc_active_streams(intel_dp);
        drm_WARN_ON(display->drm, DISPLAY_VER(display) >= 12 && first_mst_stream &&
                    !intel_dp_mst_is_master_trans(pipe_config));
 
-       drm_dbg_kms(display->drm, "active links %d\n",
-                   intel_dp->mst.active_links);
-
        if (first_mst_stream)
                intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
 
@@ -1215,8 +1231,6 @@ static void mst_stream_pre_enable(struct intel_atomic_state *state,
                intel_mst_reprobe_topology(intel_dp, pipe_config);
        }
 
-       intel_dp->mst.active_links++;
-
        ret = drm_dp_add_payload_part1(&intel_dp->mst.mgr, mst_state,
                                       drm_atomic_get_mst_payload_state(mst_state, connector->mst.port));
        if (ret < 0)
@@ -1335,9 +1349,6 @@ static void mst_stream_enable(struct intel_atomic_state *state,
        intel_de_rmw(display, TRANS_DDI_FUNC_CTL(display, trans), 0,
                     TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
 
-       drm_dbg_kms(display->drm, "active links %d\n",
-                   intel_dp->mst.active_links);
-
        intel_ddi_wait_for_act_sent(encoder, pipe_config);
        drm_dp_check_act_status(&intel_dp->mst.mgr);