Add a missing mutex lock to control vblank irq. Thus prevent race
conditions when registering/unregistering the irq callback.

v2: Slightly changed wording of commit message
v3: Mistakenly did not change wording in last version. It is done now.

Signed-off-by: Paloma Arellano <quic_parel...@quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c          | 6 ++++++
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h     | 6 ++++++
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 2 ++
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 2 ++
 4 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c 
b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 1cf7ff6caff4e..19ff7d1d5ccad 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -119,6 +119,8 @@ enum dpu_enc_rc_states {
  *     Virtual encoder defers as much as possible to the physical encoders.
  *     Virtual encoder registers itself with the DRM Framework as the encoder.
  * @base:              drm_encoder base class for registration with DRM
+ * @vblank_ctl_lock:   Vblank ctl mutex lock to protect physical encoder
+ *                                             for IRQ purposes
  * @enc_spinlock:      Virtual-Encoder-Wide Spin Lock for IRQ purposes
  * @enabled:           True if the encoder is active, protected by enc_lock
  * @num_phys_encs:     Actual number of physical encoders contained.
@@ -166,6 +168,7 @@ enum dpu_enc_rc_states {
  */
 struct dpu_encoder_virt {
        struct drm_encoder base;
+       struct mutex vblank_ctl_lock;
        spinlock_t enc_spinlock;
 
        bool enabled;
@@ -2255,6 +2258,7 @@ static int dpu_encoder_setup_display(struct 
dpu_encoder_virt *dpu_enc,
        phys_params.dpu_kms = dpu_kms;
        phys_params.parent = &dpu_enc->base;
        phys_params.enc_spinlock = &dpu_enc->enc_spinlock;
+       phys_params.vblank_ctl_lock = &dpu_enc->vblank_ctl_lock;
 
        WARN_ON(disp_info->num_of_h_tiles < 1);
 
@@ -2386,6 +2390,7 @@ struct drm_encoder *dpu_encoder_init(struct drm_device 
*dev,
        dpu_enc->enabled = false;
        mutex_init(&dpu_enc->enc_lock);
        mutex_init(&dpu_enc->rc_lock);
+       mutex_init(&dpu_enc->vblank_ctl_lock);
 
        ret = dpu_encoder_setup_display(dpu_enc, dpu_kms, disp_info);
        if (ret)
@@ -2495,6 +2500,7 @@ void dpu_encoder_phys_init(struct dpu_encoder_phys 
*phys_enc,
        phys_enc->dpu_kms = p->dpu_kms;
        phys_enc->split_role = p->split_role;
        phys_enc->enc_spinlock = p->enc_spinlock;
+       phys_enc->vblank_ctl_lock = p->vblank_ctl_lock;
        phys_enc->enable_state = DPU_ENC_DISABLED;
 
        atomic_set(&phys_enc->vblank_refcount, 0);
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 6f04c3d56e77c..5691bf6b82ee6 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
@@ -155,6 +155,8 @@ enum dpu_intr_idx {
  * @hw_wb:             Hardware interface to the wb registers
  * @dpu_kms:           Pointer to the dpu_kms top level
  * @cached_mode:       DRM mode cached at mode_set time, acted on in enable
+ * @vblank_ctl_lock:   Vblank ctl mutex lock to protect physical encoder
+ *                                             for IRQ purposes
  * @enabled:           Whether the encoder has enabled and running a mode
  * @split_role:                Role to play in a split-panel configuration
  * @intf_mode:         Interface mode
@@ -183,6 +185,7 @@ struct dpu_encoder_phys {
        struct dpu_hw_wb *hw_wb;
        struct dpu_kms *dpu_kms;
        struct drm_display_mode cached_mode;
+       struct mutex *vblank_ctl_lock;
        enum dpu_enc_split_role split_role;
        enum dpu_intf_mode intf_mode;
        spinlock_t *enc_spinlock;
@@ -253,6 +256,8 @@ struct dpu_encoder_phys_cmd {
  * @split_role:                Role to play in a split-panel configuration
  * @hw_intf:           Hardware interface to the intf registers
  * @hw_wb:             Hardware interface to the wb registers
+ * @vblank_ctl_lock:   Vblank ctl mutex lock to protect physical encoder
+ *                                             for IRQ purposes
  * @enc_spinlock:      Virtual-Encoder-Wide Spin Lock for IRQ purposes
  */
 struct dpu_enc_phys_init_params {
@@ -261,6 +266,7 @@ struct dpu_enc_phys_init_params {
        enum dpu_enc_split_role split_role;
        struct dpu_hw_intf *hw_intf;
        struct dpu_hw_wb *hw_wb;
+       struct mutex *vblank_ctl_lock;
        spinlock_t *enc_spinlock;
 };
 
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 25babfe1f001a..dcf1f6a18ad6e 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
@@ -244,6 +244,7 @@ static int dpu_encoder_phys_cmd_control_vblank_irq(
                return -EINVAL;
        }
 
+       mutex_lock(phys_enc->vblank_ctl_lock);
        refcount = atomic_read(&phys_enc->vblank_refcount);
 
        /* Slave encoders don't report vblank */
@@ -275,6 +276,7 @@ static int dpu_encoder_phys_cmd_control_vblank_irq(
        }
 
 end:
+       mutex_unlock(phys_enc->vblank_ctl_lock);
        if (ret) {
                DRM_ERROR("vblank irq err id:%u pp:%d ret:%d, enable %s/%d\n",
                          DRMID(phys_enc->parent),
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 8e905d7267f9f..87bb49763785d 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
@@ -364,6 +364,7 @@ static int dpu_encoder_phys_vid_control_vblank_irq(
        int ret = 0;
        int refcount;
 
+       mutex_lock(phys_enc->vblank_ctl_lock);
        refcount = atomic_read(&phys_enc->vblank_refcount);
 
        /* Slave encoders don't report vblank */
@@ -394,6 +395,7 @@ static int dpu_encoder_phys_vid_control_vblank_irq(
        }
 
 end:
+       mutex_unlock(phys_enc->vblank_ctl_lock);
        if (ret) {
                DRM_ERROR("failed: id:%u intf:%d ret:%d enable:%d refcnt:%d\n",
                          DRMID(phys_enc->parent),
-- 
2.41.0

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