On 08/02/2023 23:37, Jessica Zhang wrote:
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]
[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@xxxxxxxxxxx>
---
.../drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 78 ++++++++++---------
1 file changed, 43 insertions(+), 35 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 279a0b7015ce..746250bce3d1 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
@@ -587,39 +587,6 @@ static void dpu_encoder_phys_cmd_destroy(struct dpu_encoder_phys *phys_enc)
kfree(cmd_enc);
}
-static void dpu_encoder_phys_cmd_prepare_for_kickoff(
- struct dpu_encoder_phys *phys_enc)
-{
- struct dpu_encoder_phys_cmd *cmd_enc =
- to_dpu_encoder_phys_cmd(phys_enc);
- int ret;
-
- if (!phys_enc->hw_pp) {
- DPU_ERROR("invalid encoder\n");
- return;
- }
- DRM_DEBUG_KMS("id:%u pp:%d pending_cnt:%d\n", DRMID(phys_enc->parent),
- phys_enc->hw_pp->idx - PINGPONG_0,
- atomic_read(&phys_enc->pending_kickoff_cnt));
-
- /*
- * Mark kickoff request as outstanding. If there are more than one,
- * outstanding, then we have to wait for the previous one to complete
- */
- ret = _dpu_encoder_phys_cmd_wait_for_idle(phys_enc);
- if (ret) {
- /* force pending_kickoff_cnt 0 to discard failed kickoff */
- atomic_set(&phys_enc->pending_kickoff_cnt, 0);
- DRM_ERROR("failed wait_for_idle: id:%u ret:%d pp:%d\n",
- DRMID(phys_enc->parent), ret,
- phys_enc->hw_pp->idx - PINGPONG_0);
- }
-
- 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));
-}
-
static bool dpu_encoder_phys_cmd_is_ongoing_pptx(
struct dpu_encoder_phys *phys_enc)
{
@@ -645,8 +612,7 @@ 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);
@@ -704,6 +670,48 @@ static void dpu_encoder_phys_cmd_prepare_commit(
"disabled autorefresh\n");
}
+static void dpu_encoder_phys_cmd_prepare_for_kickoff(
+ struct dpu_encoder_phys *phys_enc)
Could you please move the function back to the place, so that we can see
the actual difference?
+{
+ struct dpu_encoder_phys_cmd *cmd_enc =
+ to_dpu_encoder_phys_cmd(phys_enc);
+ int ret;
+
+ if (!phys_enc->hw_pp) {
+ DPU_ERROR("invalid encoder\n");
+ return;
+ }
+
+
+ DRM_DEBUG_KMS("id:%u pp:%d pending_cnt:%d\n", DRMID(phys_enc->parent),
+ phys_enc->hw_pp->idx - PINGPONG_0,
+ atomic_read(&phys_enc->pending_kickoff_cnt));
+
+ /*
+ * Mark kickoff request as outstanding. If there are more than one,
+ * outstanding, then we have to wait for the previous one to complete
+ */
+ ret = _dpu_encoder_phys_cmd_wait_for_idle(phys_enc);
+ if (ret) {
+ /* force pending_kickoff_cnt 0 to discard failed kickoff */
+ atomic_set(&phys_enc->pending_kickoff_cnt, 0);
+ DRM_ERROR("failed wait_for_idle: id:%u ret:%d pp:%d\n",
+ DRMID(phys_enc->parent), ret,
+ 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));
+}
+
+static void dpu_encoder_phys_cmd_prepare_commit(
+ struct dpu_encoder_phys *phys_enc)
+{
+}
There is no need to have the empty callback, you can skip it completely.
Actually, if it is not needed anymore for the cmd encoders, you can drop
the .prepare_commit from struct dpu_encoder_phys_ops. And then, by
extension, dpu_encoder_prepare_commit(), dpu_kms_prepare_commit(). This
sounds like a nice second patch for this rfc.
+
static int _dpu_encoder_phys_cmd_wait_for_ctl_start(
struct dpu_encoder_phys *phys_enc)
{
--
With best wishes
Dmitry
