[Intel-gfx] [PATCH v2 1/6] drm/i915: Correctly populate use_sagv_wm for all pipes

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

When changing between SAGV vs. no SAGV on tgl+ we have to
update the use_sagv_wm flag for all the crtcs or else
an active pipe not already in the state will end up using
the wrong watermarks. That is especially bad when we end up
with the tighter non-SAGV watermarks with SAGV enabled.
Usually ends up in underruns.

Cc: stable at vger.kernel.org
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Fixes: 7241c57d3140 ("drm/i915: Add TGL+ SAGV support")
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 9f5e3c399f8d..bd32fd70e6b2 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4007,6 +4007,17 @@ static int intel_compute_sagv_mask(struct intel_atomic_state *state)
 			return ret;
 	}
 
+	if (intel_can_enable_sagv(dev_priv, new_bw_state) !=
+	    intel_can_enable_sagv(dev_priv, old_bw_state)) {
+		ret = intel_atomic_serialize_global_state(&new_bw_state->base);
+		if (ret)
+			return ret;
+	} else if (new_bw_state->pipe_sagv_reject != old_bw_state->pipe_sagv_reject) {
+		ret = intel_atomic_lock_global_state(&new_bw_state->base);
+		if (ret)
+			return ret;
+	}
+
 	for_each_new_intel_crtc_in_state(state, crtc,
 					 new_crtc_state, i) {
 		struct skl_pipe_wm *pipe_wm = &new_crtc_state->wm.skl.optimal;
@@ -4022,17 +4033,6 @@ static int intel_compute_sagv_mask(struct intel_atomic_state *state)
 			intel_can_enable_sagv(dev_priv, new_bw_state);
 	}
 
-	if (intel_can_enable_sagv(dev_priv, new_bw_state) !=
-	    intel_can_enable_sagv(dev_priv, old_bw_state)) {
-		ret = intel_atomic_serialize_global_state(&new_bw_state->base);
-		if (ret)
-			return ret;
-	} else if (new_bw_state->pipe_sagv_reject != old_bw_state->pipe_sagv_reject) {
-		ret = intel_atomic_lock_global_state(&new_bw_state->base);
-		if (ret)
-			return ret;
-	}
-
 	return 0;
 }
 
-- 
2.34.1