[PATCH 2/8] drm/msm/dpu: save LMs in encoder mode_set for cleanup use later

From: Xi Zhang via B4 Relay

Date: Mon Oct 26 2026 - 15:20:52 EST


From: Xi Zhang <xz.ca.cn@xxxxxxxxx>

dpu_encoder_helper_reset_mixers, which is called during atomic_commit
disable phase, previously called
dpu_kms_get_existing_global_state, which returns the global_state
after the state swap. So the cleanup was performed on the newly
allocated resources instead of the ones that actually need reset.

Cache LMs in dpu_enc similar to other resources during mode set, and
perform the cleanup on cached LMs instead.

Also removed redundant ctl->ops.setup_blendstage during cleanup since
ctl->ops.clear_all_blendstages covers it already.

Signed-off-by: Xi Zhang <xz.ca.cn@xxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 57 +++++++++++++++--------------
1 file changed, 30 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 8d2b4d2726f2..09afc0681248 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -133,6 +133,7 @@ enum dpu_enc_rc_states {
* @cur_master: Pointer to the current master in this mode. Optimization
* Only valid after enable. Cleared as disable.
* @cur_slave: As above but for the slave encoder.
+ * @hw_mixer: Handle to the layer mixers used for the display.
* @hw_pp: Handle to the pingpong blocks used for the display. No.
* pingpong blocks can be different than num_phys_encs.
* @hw_cwb: Handle to the CWB muxes used for concurrent writeback
@@ -182,6 +183,7 @@ struct dpu_encoder_virt {
struct dpu_encoder_phys *phys_encs[MAX_PHYS_ENCODERS_PER_VIRTUAL];
struct dpu_encoder_phys *cur_master;
struct dpu_encoder_phys *cur_slave;
+ struct dpu_hw_mixer *hw_mixer[MAX_CHANNELS_PER_ENC];
struct dpu_hw_pingpong *hw_pp[MAX_CHANNELS_PER_ENC];
struct dpu_hw_cwb *hw_cwb[MAX_CWB_PER_ENC];
struct dpu_hw_dsc *hw_dsc[MAX_CHANNELS_PER_ENC];
@@ -1156,11 +1158,12 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
struct msm_drm_private *priv;
struct dpu_kms *dpu_kms;
struct dpu_global_state *global_state;
+ struct dpu_hw_blk *hw_lm[MAX_CHANNELS_PER_ENC];
struct dpu_hw_blk *hw_pp[MAX_CHANNELS_PER_ENC];
struct dpu_hw_blk *hw_ctl[MAX_CHANNELS_PER_ENC];
struct dpu_hw_blk *hw_dsc[MAX_CHANNELS_PER_ENC];
struct dpu_hw_blk *hw_cwb[MAX_CHANNELS_PER_ENC];
- int num_ctl, num_pp, num_dsc, num_pp_per_intf;
+ int num_ctl, num_lm, num_pp, num_dsc, num_pp_per_intf;
int num_cwb = 0;
bool is_cwb_encoder;
unsigned int dsc_mask = 0;
@@ -1189,6 +1192,14 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
trace_dpu_enc_mode_set(DRMID(drm_enc));

/* Query resource that have been reserved in atomic check step. */
+
+ num_lm = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
+ drm_enc->crtc, DPU_HW_BLK_LM, hw_lm, ARRAY_SIZE(hw_lm));
+
+ for (i = 0; i < ARRAY_SIZE(dpu_enc->hw_mixer); i++)
+ dpu_enc->hw_mixer[i] = i < num_lm ? to_dpu_hw_mixer(hw_lm[i])
+ : NULL;
+
if (is_cwb_encoder) {
num_pp = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
drm_enc->crtc,
@@ -2183,42 +2194,34 @@ void dpu_encoder_kickoff(struct drm_encoder *drm_enc)

static void dpu_encoder_helper_reset_mixers(struct dpu_encoder_phys *phys_enc)
{
- int i, num_lm;
- struct dpu_global_state *global_state;
- struct dpu_hw_blk *hw_lm[2];
- struct dpu_hw_mixer *hw_mixer[2];
+ int i;
struct dpu_hw_ctl *ctl = phys_enc->hw_ctl;
+ struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(phys_enc->parent);

/* reset all mixers for this encoder */
if (ctl->ops.clear_all_blendstages)
ctl->ops.clear_all_blendstages(ctl);

- global_state = dpu_kms_get_existing_global_state(phys_enc->dpu_kms);
+ for (i = 0; i < ARRAY_SIZE(dpu_enc->hw_mixer); i++) {
+ if (dpu_enc->hw_mixer[i]) {
+ if (ctl->ops.update_pending_flush_mixer)
+ ctl->ops.update_pending_flush_mixer(ctl, dpu_enc->hw_mixer[i]->idx);

- num_lm = dpu_rm_get_assigned_resources(&phys_enc->dpu_kms->rm, global_state,
- phys_enc->parent->crtc, DPU_HW_BLK_LM, hw_lm, ARRAY_SIZE(hw_lm));
-
- for (i = 0; i < num_lm; i++) {
- hw_mixer[i] = to_dpu_hw_mixer(hw_lm[i]);
- if (ctl->ops.update_pending_flush_mixer)
- ctl->ops.update_pending_flush_mixer(ctl, hw_mixer[i]->idx);
-
- /* clear all blendstages */
- if (ctl->ops.setup_blendstage)
- ctl->ops.setup_blendstage(ctl, hw_mixer[i]->idx, NULL);
-
- if (hw_mixer[i]->ops.clear_all_blendstages)
- hw_mixer[i]->ops.clear_all_blendstages(hw_mixer[i]);
+ /* clear all blendstages */
+ if (dpu_enc->hw_mixer[i]->ops.clear_all_blendstages)
+ dpu_enc->hw_mixer[i]->ops.clear_all_blendstages(
+ dpu_enc->hw_mixer[i]);
+ }
+ }

- if (ctl->ops.set_active_lms)
- ctl->ops.set_active_lms(ctl, NULL);
+ if (ctl->ops.set_active_lms)
+ ctl->ops.set_active_lms(ctl, NULL);

- if (ctl->ops.set_active_fetch_pipes)
- ctl->ops.set_active_fetch_pipes(ctl, NULL);
+ if (ctl->ops.set_active_fetch_pipes)
+ ctl->ops.set_active_fetch_pipes(ctl, NULL);

- if (ctl->ops.set_active_pipes)
- ctl->ops.set_active_pipes(ctl, NULL);
- }
+ if (ctl->ops.set_active_pipes)
+ ctl->ops.set_active_pipes(ctl, NULL);
}

static void dpu_encoder_dsc_pipe_clr(struct dpu_hw_ctl *ctl,

--
2.55.0