[PATCH 2/2] drm/msm/dpu: Add mutex lock in control vblank irq

[Paloma Arellano]

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

Signed-off-by: Paloma Arellano <quic_parellan at 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),
-- 
2.39.2