From: Paloma Arellano quic_parellan@quicinc.com
[ Upstream commit 45284ff733e4caf6c118aae5131eb7e7cf3eea5a ]
Add a mutex lock to control vblank irq to synchronize vblank enable/disable operations happening from different threads to prevent race conditions while registering/unregistering the vblank irq callback.
v4: -Removed vblank_ctl_lock from dpu_encoder_virt, so it is only a parameter of dpu_encoder_phys. -Switch from atomic refcnt to a simple int counter as mutex has now been added v3: Mistakenly did not change wording in last version. It is done now. v2: Slightly changed wording of commit message
Signed-off-by: Paloma Arellano quic_parellan@quicinc.com Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Patchwork: https://patchwork.freedesktop.org/patch/571854/ Link: https://lore.kernel.org/r/20231212231101.9240-2-quic_parellan@quicinc.com Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 1 - .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h | 4 ++- .../drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 32 ++++++++++++------ .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 33 ++++++++++++------- 4 files changed, 47 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c index ff0e3591b44d..289e4a615a08 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c @@ -2500,7 +2500,6 @@ void dpu_encoder_phys_init(struct dpu_encoder_phys *phys_enc, phys_enc->enc_spinlock = p->enc_spinlock; phys_enc->enable_state = DPU_ENC_DISABLED;
- atomic_set(&phys_enc->vblank_refcount, 0); atomic_set(&phys_enc->pending_kickoff_cnt, 0); atomic_set(&phys_enc->pending_ctlstart_cnt, 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 6f04c3d56e77..96bda57b6959 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 +155,7 @@ 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 vblank_refcount * @enabled: Whether the encoder has enabled and running a mode * @split_role: Role to play in a split-panel configuration * @intf_mode: Interface mode @@ -183,11 +184,12 @@ 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; enum dpu_enc_enable_state enable_state; - atomic_t vblank_refcount; + int vblank_refcount; atomic_t vsync_cnt; atomic_t underrun_cnt; atomic_t pending_ctlstart_cnt; 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 be185fe69793..2d788c5e26a8 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 @@ -244,7 +244,8 @@ static int dpu_encoder_phys_cmd_control_vblank_irq( return -EINVAL; }
- refcount = atomic_read(&phys_enc->vblank_refcount); + mutex_lock(&phys_enc->vblank_ctl_lock); + refcount = phys_enc->vblank_refcount;
/* Slave encoders don't report vblank */ if (!dpu_encoder_phys_cmd_is_master(phys_enc)) @@ -260,16 +261,24 @@ static int dpu_encoder_phys_cmd_control_vblank_irq( phys_enc->hw_pp->idx - PINGPONG_0, enable ? "true" : "false", refcount);
- if (enable && atomic_inc_return(&phys_enc->vblank_refcount) == 1) - ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_RDPTR], - dpu_encoder_phys_cmd_te_rd_ptr_irq, - phys_enc); - else if (!enable && atomic_dec_return(&phys_enc->vblank_refcount) == 0) - ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_RDPTR]); + if (enable) { + if (phys_enc->vblank_refcount == 0) + ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_RDPTR], + dpu_encoder_phys_cmd_te_rd_ptr_irq, + phys_enc); + if (!ret) + phys_enc->vblank_refcount++; + } else if (!enable) { + if (phys_enc->vblank_refcount == 1) + ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_RDPTR]); + if (!ret) + phys_enc->vblank_refcount--; + }
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), @@ -285,7 +294,7 @@ static void dpu_encoder_phys_cmd_irq_control(struct dpu_encoder_phys *phys_enc, { trace_dpu_enc_phys_cmd_irq_ctrl(DRMID(phys_enc->parent), phys_enc->hw_pp->idx - PINGPONG_0, - enable, atomic_read(&phys_enc->vblank_refcount)); + enable, phys_enc->vblank_refcount);
if (enable) { dpu_core_irq_register_callback(phys_enc->dpu_kms, @@ -763,6 +772,9 @@ struct dpu_encoder_phys *dpu_encoder_phys_cmd_init(
dpu_encoder_phys_init(phys_enc, p);
+ mutex_init(&phys_enc->vblank_ctl_lock); + phys_enc->vblank_refcount = 0; + dpu_encoder_phys_cmd_init_ops(&phys_enc->ops); phys_enc->intf_mode = INTF_MODE_CMD; cmd_enc->stream_sel = 0; 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 a01fda711883..eeb0acf9665e 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 @@ -364,7 +364,8 @@ static int dpu_encoder_phys_vid_control_vblank_irq( int ret = 0; int refcount;
- refcount = atomic_read(&phys_enc->vblank_refcount); + mutex_lock(&phys_enc->vblank_ctl_lock); + refcount = phys_enc->vblank_refcount;
/* Slave encoders don't report vblank */ if (!dpu_encoder_phys_vid_is_master(phys_enc)) @@ -377,18 +378,26 @@ static int dpu_encoder_phys_vid_control_vblank_irq( }
DRM_DEBUG_VBL("id:%u enable=%d/%d\n", DRMID(phys_enc->parent), enable, - atomic_read(&phys_enc->vblank_refcount)); + refcount);
- if (enable && atomic_inc_return(&phys_enc->vblank_refcount) == 1) - ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_VSYNC], - dpu_encoder_phys_vid_vblank_irq, - phys_enc); - else if (!enable && atomic_dec_return(&phys_enc->vblank_refcount) == 0) - ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, - phys_enc->irq[INTR_IDX_VSYNC]); + if (enable) { + if (phys_enc->vblank_refcount == 0) + ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_VSYNC], + dpu_encoder_phys_vid_vblank_irq, + phys_enc); + if (!ret) + phys_enc->vblank_refcount++; + } else if (!enable) { + if (phys_enc->vblank_refcount == 1) + ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, + phys_enc->irq[INTR_IDX_VSYNC]); + if (!ret) + phys_enc->vblank_refcount--; + }
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), @@ -618,7 +627,7 @@ static void dpu_encoder_phys_vid_irq_control(struct dpu_encoder_phys *phys_enc, trace_dpu_enc_phys_vid_irq_ctrl(DRMID(phys_enc->parent), phys_enc->hw_intf->idx - INTF_0, enable, - atomic_read(&phys_enc->vblank_refcount)); + phys_enc->vblank_refcount);
if (enable) { ret = dpu_encoder_phys_vid_control_vblank_irq(phys_enc, true); @@ -713,6 +722,8 @@ struct dpu_encoder_phys *dpu_encoder_phys_vid_init( DPU_DEBUG_VIDENC(phys_enc, "\n");
dpu_encoder_phys_init(phys_enc, p); + mutex_init(&phys_enc->vblank_ctl_lock); + phys_enc->vblank_refcount = 0;
dpu_encoder_phys_vid_init_ops(&phys_enc->ops); phys_enc->intf_mode = INTF_MODE_VIDEO;