[RFC PATCH v3 1/4] drm/msm/dpu: Move TE setup to prepare_for_kickoff()

[Jessica Zhang]

Currently, DPU will enable TE during prepare_commit(). However, this
will cause issues when trying to read/write to register in
get_autorefresh_config(), because the core clock rates aren't set at
that time.

This used to work because phys_enc->hw_pp is only initialized in mode
set [1], so the first prepare_commit() will return before any register
read/write as hw_pp would be NULL.

However, when we try to implement support for INTF TE, we will run into
the clock issue described above as hw_intf will *not* be NULL on the
first prepare_commit(). This is because the initialization of
dpu_enc->hw_intf has been moved to dpu_encoder_setup() [2].

To avoid this issue, let's enable TE during prepare_for_kickoff()
instead as the core clock rates are guaranteed to be set then.

Depends on: "Implement tearcheck support on INTF block" [3]

Changes in V3:
- Added function prototypes
- Reordered function definitions to make change more legible
- Removed prepare_commit() function from dpu_encoder_phys_cmd

[1] https://gitlab.freedesktop.org/drm/msm/-/blob/msm-next/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c#L1109
[2] https://gitlab.freedesktop.org/drm/msm/-/blob/msm-next/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c#L2339
[3] https://patchwork.freedesktop.org/series/112332/

Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
index cb05036f2916..c6feffafa13f 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
@@ -40,6 +40,10 @@
 
 #define DPU_ENC_MAX_POLL_TIMEOUT_US	2000
 
+static bool dpu_encoder_phys_cmd_is_ongoing_pptx(
+		struct dpu_encoder_phys *phys_enc);
+static void dpu_encoder_phys_cmd_enable_te(struct dpu_encoder_phys *phys_enc);
+
 static bool dpu_encoder_phys_cmd_is_master(struct dpu_encoder_phys *phys_enc)
 {
 	return (phys_enc->split_role != ENC_ROLE_SLAVE);
@@ -611,6 +615,8 @@ static void dpu_encoder_phys_cmd_prepare_for_kickoff(
 			  phys_enc->hw_pp->idx - PINGPONG_0);
 	}
 
+	dpu_encoder_phys_cmd_enable_te(phys_enc);
+
 	DPU_DEBUG_CMDENC(cmd_enc, "pp:%d pending_cnt %d\n",
 			phys_enc->hw_pp->idx - PINGPONG_0,
 			atomic_read(&phys_enc->pending_kickoff_cnt));
@@ -641,8 +647,7 @@ static bool dpu_encoder_phys_cmd_is_ongoing_pptx(
 	return false;
 }
 
-static void dpu_encoder_phys_cmd_prepare_commit(
-		struct dpu_encoder_phys *phys_enc)
+static void dpu_encoder_phys_cmd_enable_te(struct dpu_encoder_phys *phys_enc)
 {
 	struct dpu_encoder_phys_cmd *cmd_enc =
 		to_dpu_encoder_phys_cmd(phys_enc);
@@ -799,7 +804,6 @@ static void dpu_encoder_phys_cmd_trigger_start(
 static void dpu_encoder_phys_cmd_init_ops(
 		struct dpu_encoder_phys_ops *ops)
 {
-	ops->prepare_commit = dpu_encoder_phys_cmd_prepare_commit;
 	ops->is_master = dpu_encoder_phys_cmd_is_master;
 	ops->atomic_mode_set = dpu_encoder_phys_cmd_atomic_mode_set;
 	ops->enable = dpu_encoder_phys_cmd_enable;
-- 
2.39.1