drm/i915/display: Refactor intel_commit_modeset_disables()

Commit 9c722e17c1b9 ("drm/i915: Disable pipes in reverse order")
reverted the order that pipes gets disabled because of TGL
master/slave relationship between transcoders in MST mode.

But as stated in a comment in skl_commit_modeset_enables() the
enabling order is not always crescent, possibly causing previously
selected slave transcoder being enabled before master so another
approach will be needed to select a transcoder to master in MST mode.
It will be similar to the approach taken in port sync.

But instead of implement something like
intel_trans_port_sync_modeset_disables() to MST lets simply it and
iterate over all pipes 2 times, the first one disabling any slave and
then disabling everything else.
The MST bits will be added in another patch.

v2:
Not using crtc->active as it is deprecated

v3:
Removing is_trans_port_sync_mode() check, just check for
is_trans_port_sync_master() is enough

v4:
Adding and using is_trans_port_sync_slave(), otherwise non-port sync
pipes will be disabled in the first loop, what is not wrong but is
not what patch description promises

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v2)
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191205210350.96795-3-jose.souza@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index cd8a171..a35ec8e 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -561,6 +561,12 @@ is_trans_port_sync_master(const struct intel_crtc_state *crtc_state)
                crtc_state->sync_mode_slaves_mask);
 }
 
+static bool
+is_trans_port_sync_slave(const struct intel_crtc_state *crtc_state)
+{
+       return crtc_state->master_transcoder != INVALID_TRANSCODER;
+}
+
 /*
  * Platform specific helpers to calculate the port PLL loopback- (clock.m),
  * and post-divider (clock.p) values, pre- (clock.vco) and post-divided fast
@@ -14393,77 +14399,47 @@ static void intel_old_crtc_state_disables(struct intel_atomic_state *state,
                dev_priv->display.initial_watermarks(state, crtc);
 }
 
-static void intel_trans_port_sync_modeset_disables(struct intel_atomic_state *state,
-                                                  struct intel_crtc *crtc,
-                                                  struct intel_crtc_state *old_crtc_state,
-                                                  struct intel_crtc_state *new_crtc_state)
-{
-       struct intel_crtc *slave_crtc = intel_get_slave_crtc(new_crtc_state);
-       struct intel_crtc_state *new_slave_crtc_state =
-               intel_atomic_get_new_crtc_state(state, slave_crtc);
-       struct intel_crtc_state *old_slave_crtc_state =
-               intel_atomic_get_old_crtc_state(state, slave_crtc);
-
-       WARN_ON(!slave_crtc || !new_slave_crtc_state ||
-               !old_slave_crtc_state);
-
-       /* Disable Slave first */
-       intel_pre_plane_update(state, slave_crtc);
-       if (old_slave_crtc_state->hw.active)
-               intel_old_crtc_state_disables(state,
-                                             old_slave_crtc_state,
-                                             new_slave_crtc_state,
-                                             slave_crtc);
-
-       /* Disable Master */
-       intel_pre_plane_update(state, crtc);
-       if (old_crtc_state->hw.active)
-               intel_old_crtc_state_disables(state,
-                                             old_crtc_state,
-                                             new_crtc_state,
-                                             crtc);
-}
-
 static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 {
        struct intel_crtc_state *new_crtc_state, *old_crtc_state;
        struct intel_crtc *crtc;
+       u32 handled = 0;
        int i;
 
-       /*
-        * Disable CRTC/pipes in reverse order because some features(MST in
-        * TGL+) requires master and slave relationship between pipes, so it
-        * should always pick the lowest pipe as master as it will be enabled
-        * first and disable in the reverse order so the master will be the
-        * last one to be disabled.
-        */
-       for_each_oldnew_intel_crtc_in_state_reverse(state, crtc, old_crtc_state,
-                                                   new_crtc_state, i) {
+       /* Only disable port sync slaves */
+       for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
+                                           new_crtc_state, i) {
                if (!needs_modeset(new_crtc_state))
                        continue;
 
+               if (!old_crtc_state->hw.active)
+                       continue;
+
                /* In case of Transcoder port Sync master slave CRTCs can be
                 * assigned in any order and we need to make sure that
                 * slave CRTCs are disabled first and then master CRTC since
                 * Slave vblanks are masked till Master Vblanks.
                 */
-               if (is_trans_port_sync_mode(old_crtc_state)) {
-                       if (is_trans_port_sync_master(old_crtc_state))
-                               intel_trans_port_sync_modeset_disables(state,
-                                                                      crtc,
-                                                                      old_crtc_state,
-                                                                      new_crtc_state);
-                       else
-                               continue;
-               } else {
-                       intel_pre_plane_update(state, crtc);
+               if (!is_trans_port_sync_slave(old_crtc_state))
+                       continue;
 
-                       if (old_crtc_state->hw.active)
-                               intel_old_crtc_state_disables(state,
-                                                             old_crtc_state,
-                                                             new_crtc_state,
-                                                             crtc);
-               }
+               intel_pre_plane_update(state, crtc);
+               intel_old_crtc_state_disables(state, old_crtc_state,
+                                             new_crtc_state, crtc);
+               handled |= BIT(crtc->pipe);
+       }
+
+       /* Disable everything else left on */
+       for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
+                                           new_crtc_state, i) {
+               if (!needs_modeset(new_crtc_state) ||
+                   (handled & BIT(crtc->pipe)))
+                       continue;
+
+               intel_pre_plane_update(state, crtc);
+               if (old_crtc_state->hw.active)
+                       intel_old_crtc_state_disables(state, old_crtc_state,
+                                                     new_crtc_state, crtc);
        }
 }