diff mbox series

[v9,05/14] drm/msm/dpu: fix mixer number counter on allocation

Message ID 20250506-quad-pipe-upstream-v9-5-f7b273a8cc80@linaro.org
State New
Headers show
Series [v9,01/14] drm/atomic-helper: Add crtc check before checking plane | expand

Commit Message

Jun Nie May 6, 2025, 3:47 p.m. UTC 
Current code only supports usage cases with one pair of mixers at
most. To support quad-pipe usage case, two pairs of mixers need to
be reserved. The lm_count for all pairs is cleared if a peer
allocation fails in current implementation. Reset the current lm_count
to an even number instead of completely clearing it. This prevents all
pairs from being cleared in cases where multiple LM pairs are needed.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
index 2d8ff4b524715c658188fe56bc337e3ffa831c0a..bc7639a46386c6b9457edf3afdf6f747a632651f 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
@@ -374,7 +374,11 @@  static int _dpu_rm_reserve_lms(struct dpu_rm *rm,
 		if (!rm->mixer_blks[i])
 			continue;
 
-		lm_count = 0;
+		/*
+		 * Reset lm_count to an even index. This will drop the previous
+		 * primary mixer if failed to find its peer.
+		 */
+		lm_count &= ~1;
 		lm_idx[lm_count] = i;
 
 		if (!_dpu_rm_check_lm_and_get_connected_blks(rm, global_state,