[PATCH v2 1/2] drm/i915/display: Reject flipq for commits with no plane updates

[Mika Kahola <mika.kahola@intel.com>]

flipq is pointless without an actual plane update to queue. Reject it.

v2:
- Drop the single-plane restriction, plane count doesn't matter (Ville)
- Drop the update_wm_pre/post check, dead code for flipq-capable hw (Ville)
- Drop the active/enabled planes check (Ville)
- Drop the update_pipe/update_m_n/update_lrr check -- unreachable,
  intel_crtc_needs_fastset() above is exactly update_pipe, and
  update_m_n/update_lrr can only be set alongside it or a full modeset,
  both already excluded (Sashiko AI review)
- Drop the intel_flipq_commit_is_eligible() helper -- with the above
  gone, all that's left is one extra check, not worth its own function
  for a single call site

Assisted-by: Copilot:claude-sonnet-5
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 553c60d452dd..9272fe573ae2 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7385,6 +7385,7 @@ static void intel_atomic_dsb_prepare(struct intel_atomic_state *state,
 	/* FIXME deal with everything */
 	new_crtc_state->use_flipq =
 		intel_flipq_supported(display) &&
+		new_crtc_state->update_planes &&
 		!new_crtc_state->do_async_flip &&
 		!new_crtc_state->vrr.enable &&
 		!new_crtc_state->has_psr &&
-- 
2.43.0