[PATCH v2] Revert "drm/msm/dpu: drop dpu_encoder_phys_ops.atomic_mode_set"

From: Dmitry Baryshkov
Date: Wed May 22 2024 - 06:24:40 EST


In the DPU driver blank IRQ handling is called from a vblank worker and
can happen outside of the irq_enable / irq_disable pair. Using the
worker makes that completely asynchronous with the rest of the code.
Revert commit d13f638c9b88 ("drm/msm/dpu: drop
dpu_encoder_phys_ops.atomic_mode_set") to fix vblank IRQ assignment for
CMD DSI panels.

Call trace:
dpu_encoder_phys_cmd_control_vblank_irq+0x218/0x294
dpu_encoder_toggle_vblank_for_crtc+0x160/0x194
dpu_crtc_vblank+0xbc/0x228
dpu_kms_enable_vblank+0x18/0x24
vblank_ctrl_worker+0x34/0x6c
process_one_work+0x218/0x620
worker_thread+0x1ac/0x37c
kthread+0x114/0x118
ret_from_fork+0x10/0x20

Fixes: d13f638c9b88 ("drm/msm/dpu: drop dpu_encoder_phys_ops.atomic_mode_set")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
Changes in v2:
- Expanded commit message to describe the reason for revert and added a
call trace (Abhinav)
- Link to v1: https://lore.kernel.org/r/20240514-dpu-revert-ams-v1-1-b13623d6cd5f@xxxxxxxxxx
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 2 ++
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h | 5 ++++
.../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 32 ++++++++++++----------
.../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 13 +++++++--
.../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 11 +++++++-
5 files changed, 46 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 119f3ea50a7c..a7d8ecf3f5be 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1200,6 +1200,8 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
phys->hw_ctl = to_dpu_hw_ctl(hw_ctl[i]);

phys->cached_mode = crtc_state->adjusted_mode;
+ if (phys->ops.atomic_mode_set)
+ phys->ops.atomic_mode_set(phys, crtc_state, conn_state);
}
}

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
index 002e89cc1705..30470cd15a48 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
@@ -69,6 +69,8 @@ struct dpu_encoder_phys;
* @is_master: Whether this phys_enc is the current master
* encoder. Can be switched at enable time. Based
* on split_role and current mode (CMD/VID).
+ * @atomic_mode_set: DRM Call. Set a DRM mode.
+ * This likely caches the mode, for use at enable.
* @enable: DRM Call. Enable a DRM mode.
* @disable: DRM Call. Disable mode.
* @control_vblank_irq Register/Deregister for VBLANK IRQ
@@ -93,6 +95,9 @@ struct dpu_encoder_phys;
struct dpu_encoder_phys_ops {
void (*prepare_commit)(struct dpu_encoder_phys *encoder);
bool (*is_master)(struct dpu_encoder_phys *encoder);
+ void (*atomic_mode_set)(struct dpu_encoder_phys *encoder,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state);
void (*enable)(struct dpu_encoder_phys *encoder);
void (*disable)(struct dpu_encoder_phys *encoder);
int (*control_vblank_irq)(struct dpu_encoder_phys *enc, bool enable);
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 489be1c0c704..95cd39b49668 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
@@ -142,6 +142,23 @@ static void dpu_encoder_phys_cmd_underrun_irq(void *arg)
dpu_encoder_underrun_callback(phys_enc->parent, phys_enc);
}

+static void dpu_encoder_phys_cmd_atomic_mode_set(
+ struct dpu_encoder_phys *phys_enc,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state)
+{
+ phys_enc->irq[INTR_IDX_CTL_START] = phys_enc->hw_ctl->caps->intr_start;
+
+ phys_enc->irq[INTR_IDX_PINGPONG] = phys_enc->hw_pp->caps->intr_done;
+
+ if (phys_enc->has_intf_te)
+ phys_enc->irq[INTR_IDX_RDPTR] = phys_enc->hw_intf->cap->intr_tear_rd_ptr;
+ else
+ phys_enc->irq[INTR_IDX_RDPTR] = phys_enc->hw_pp->caps->intr_rdptr;
+
+ phys_enc->irq[INTR_IDX_UNDERRUN] = phys_enc->hw_intf->cap->intr_underrun;
+}
+
static int _dpu_encoder_phys_cmd_handle_ppdone_timeout(
struct dpu_encoder_phys *phys_enc)
{
@@ -280,14 +297,6 @@ static void dpu_encoder_phys_cmd_irq_enable(struct dpu_encoder_phys *phys_enc)
phys_enc->hw_pp->idx - PINGPONG_0,
phys_enc->vblank_refcount);

- phys_enc->irq[INTR_IDX_CTL_START] = phys_enc->hw_ctl->caps->intr_start;
- phys_enc->irq[INTR_IDX_PINGPONG] = phys_enc->hw_pp->caps->intr_done;
-
- if (phys_enc->has_intf_te)
- phys_enc->irq[INTR_IDX_RDPTR] = phys_enc->hw_intf->cap->intr_tear_rd_ptr;
- else
- phys_enc->irq[INTR_IDX_RDPTR] = phys_enc->hw_pp->caps->intr_rdptr;
-
dpu_core_irq_register_callback(phys_enc->dpu_kms,
phys_enc->irq[INTR_IDX_PINGPONG],
dpu_encoder_phys_cmd_pp_tx_done_irq,
@@ -318,10 +327,6 @@ static void dpu_encoder_phys_cmd_irq_disable(struct dpu_encoder_phys *phys_enc)
dpu_core_irq_unregister_callback(phys_enc->dpu_kms, phys_enc->irq[INTR_IDX_UNDERRUN]);
dpu_encoder_phys_cmd_control_vblank_irq(phys_enc, false);
dpu_core_irq_unregister_callback(phys_enc->dpu_kms, phys_enc->irq[INTR_IDX_PINGPONG]);
-
- phys_enc->irq[INTR_IDX_CTL_START] = 0;
- phys_enc->irq[INTR_IDX_PINGPONG] = 0;
- phys_enc->irq[INTR_IDX_RDPTR] = 0;
}

static void dpu_encoder_phys_cmd_tearcheck_config(
@@ -698,6 +703,7 @@ static void dpu_encoder_phys_cmd_init_ops(
struct dpu_encoder_phys_ops *ops)
{
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;
ops->disable = dpu_encoder_phys_cmd_disable;
ops->control_vblank_irq = dpu_encoder_phys_cmd_control_vblank_irq;
@@ -736,8 +742,6 @@ struct dpu_encoder_phys *dpu_encoder_phys_cmd_init(struct drm_device *dev,

dpu_encoder_phys_cmd_init_ops(&phys_enc->ops);
phys_enc->intf_mode = INTF_MODE_CMD;
- phys_enc->irq[INTR_IDX_UNDERRUN] = phys_enc->hw_intf->cap->intr_underrun;
-
cmd_enc->stream_sel = 0;

if (!phys_enc->hw_intf) {
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
index ef69c2f408c3..636a97432d51 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
@@ -356,6 +356,16 @@ static bool dpu_encoder_phys_vid_needs_single_flush(
return phys_enc->split_role != ENC_ROLE_SOLO;
}

+static void dpu_encoder_phys_vid_atomic_mode_set(
+ struct dpu_encoder_phys *phys_enc,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state)
+{
+ phys_enc->irq[INTR_IDX_VSYNC] = phys_enc->hw_intf->cap->intr_vsync;
+
+ phys_enc->irq[INTR_IDX_UNDERRUN] = phys_enc->hw_intf->cap->intr_underrun;
+}
+
static int dpu_encoder_phys_vid_control_vblank_irq(
struct dpu_encoder_phys *phys_enc,
bool enable)
@@ -699,6 +709,7 @@ static int dpu_encoder_phys_vid_get_frame_count(
static void dpu_encoder_phys_vid_init_ops(struct dpu_encoder_phys_ops *ops)
{
ops->is_master = dpu_encoder_phys_vid_is_master;
+ ops->atomic_mode_set = dpu_encoder_phys_vid_atomic_mode_set;
ops->enable = dpu_encoder_phys_vid_enable;
ops->disable = dpu_encoder_phys_vid_disable;
ops->control_vblank_irq = dpu_encoder_phys_vid_control_vblank_irq;
@@ -737,8 +748,6 @@ struct dpu_encoder_phys *dpu_encoder_phys_vid_init(struct drm_device *dev,

dpu_encoder_phys_vid_init_ops(&phys_enc->ops);
phys_enc->intf_mode = INTF_MODE_VIDEO;
- phys_enc->irq[INTR_IDX_VSYNC] = phys_enc->hw_intf->cap->intr_vsync;
- phys_enc->irq[INTR_IDX_UNDERRUN] = phys_enc->hw_intf->cap->intr_underrun;

DPU_DEBUG_VIDENC(phys_enc, "created intf idx:%d\n", p->hw_intf->idx);

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
index d3ea91c1d7d2..356dca5e5ea9 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
@@ -404,6 +404,15 @@ static void dpu_encoder_phys_wb_irq_disable(struct dpu_encoder_phys *phys)
dpu_core_irq_unregister_callback(phys->dpu_kms, phys->irq[INTR_IDX_WB_DONE]);
}

+static void dpu_encoder_phys_wb_atomic_mode_set(
+ struct dpu_encoder_phys *phys_enc,
+ struct drm_crtc_state *crtc_state,
+ struct drm_connector_state *conn_state)
+{
+
+ phys_enc->irq[INTR_IDX_WB_DONE] = phys_enc->hw_wb->caps->intr_wb_done;
+}
+
static void _dpu_encoder_phys_wb_handle_wbdone_timeout(
struct dpu_encoder_phys *phys_enc)
{
@@ -640,6 +649,7 @@ static bool dpu_encoder_phys_wb_is_valid_for_commit(struct dpu_encoder_phys *phy
static void dpu_encoder_phys_wb_init_ops(struct dpu_encoder_phys_ops *ops)
{
ops->is_master = dpu_encoder_phys_wb_is_master;
+ ops->atomic_mode_set = dpu_encoder_phys_wb_atomic_mode_set;
ops->enable = dpu_encoder_phys_wb_enable;
ops->disable = dpu_encoder_phys_wb_disable;
ops->wait_for_commit_done = dpu_encoder_phys_wb_wait_for_commit_done;
@@ -685,7 +695,6 @@ struct dpu_encoder_phys *dpu_encoder_phys_wb_init(struct drm_device *dev,

dpu_encoder_phys_wb_init_ops(&phys_enc->ops);
phys_enc->intf_mode = INTF_MODE_WB_LINE;
- phys_enc->irq[INTR_IDX_WB_DONE] = phys_enc->hw_wb->caps->intr_wb_done;

atomic_set(&wb_enc->wbirq_refcount, 0);


---
base-commit: 75fa778d74b786a1608d55d655d42b480a6fa8bd
change-id: 20240514-dpu-revert-ams-9410abc1ee48

Best regards,
--
Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>