Re: [PATCH 11/12] drm/msm: dpu: Add ->enabled to dpu_encoder_virt

[Jeykumar Sankaran <jsanka-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

On 2018-11-12 11:42, Sean Paul wrote:
> From: Sean Paul <seanpaul@chromium.org>
> 
> Add a bool to dpu_encoder_virt to track whether the encoder is enabled
> or not. Repurpose the enc_lock mutex to ensure that it is consistent
> with the hw state.
> 
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 27 +++++++++++++++++----
>  1 file changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 10a0676d1dcf..3daa86220d47 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -132,6 +132,7 @@ enum dpu_enc_rc_states {
>   * @base:		drm_encoder base class for registration with DRM
>   * @enc_spinlock:	Virtual-Encoder-Wide Spin Lock for IRQ purposes
>   * @bus_scaling_client:	Client handle to the bus scaling interface
> + * @enabled:		True if the encoder is active, protected by
> enc_lock
>   * @num_phys_encs:	Actual number of physical encoders contained.
>   * @phys_encs:		Container of physical encoders managed.
>   * @cur_master:		Pointer to the current master in this
> mode. Optimization
> @@ -148,8 +149,8 @@ enum dpu_enc_rc_states {
>   *				all CTL paths
>   * @crtc_kickoff_cb_data:	Opaque user data given to crtc_kickoff_cb
>   * @debugfs_root:		Debug file system root file node
> - * @enc_lock:			Lock around physical encoder
> create/destroy and
> -				access.
> + * @enc_lock:			Lock around physical encoder
> + *				create/destroy/enable/disable
>   * @frame_busy_mask:		Bitmask tracking which phys_enc we are
> still
>   *				busy processing current command.
>   *				Bit0 = phys_encs[0] etc.
> @@ -175,6 +176,8 @@ struct dpu_encoder_virt {
>  	spinlock_t enc_spinlock;
>  	uint32_t bus_scaling_client;
> 
> +	bool enabled;
> +
>  	unsigned int num_phys_encs;
>  	struct dpu_encoder_phys *phys_encs[MAX_PHYS_ENCODERS_PER_VIRTUAL];
>  	struct dpu_encoder_phys *cur_master;
> @@ -1121,6 +1124,8 @@ static void dpu_encoder_virt_enable(struct
> drm_encoder *drm_enc)
>  		return;
>  	}
>  	dpu_enc = to_dpu_encoder_virt(drm_enc);
> +
> +	mutex_lock(&dpu_enc->enc_lock);
>  	cur_mode = &dpu_enc->base.crtc->state->adjusted_mode;
> 
>  	trace_dpu_enc_enable(DRMID(drm_enc), cur_mode->hdisplay,
> @@ -1137,10 +1142,15 @@ static void dpu_encoder_virt_enable(struct
> drm_encoder *drm_enc)
>  	if (ret) {
>  		DPU_ERROR_ENC(dpu_enc, "dpu resource control failed:
> %d\n",
>  				ret);
> -		return;
> +		goto out;
>  	}
> 
>  	_dpu_encoder_virt_enable_helper(drm_enc);
> +
> +	dpu_enc->enabled = true;
> +
> +out:
> +	mutex_unlock(&dpu_enc->enc_lock);
>  }
> 
>  static void dpu_encoder_virt_disable(struct drm_encoder *drm_enc)
> @@ -1162,11 +1172,14 @@ static void dpu_encoder_virt_disable(struct
> drm_encoder *drm_enc)
>  		return;
>  	}
> 
> -	mode = &drm_enc->crtc->state->adjusted_mode;
> -
>  	dpu_enc = to_dpu_encoder_virt(drm_enc);
>  	DPU_DEBUG_ENC(dpu_enc, "\n");
> 
> +	mutex_lock(&dpu_enc->enc_lock);
Where do you expect it to go wrong if enable/disable
is not protected using enc_lock?

Thanks and Regards,
Jeykumar S.
> +	dpu_enc->enabled = false;
> +
> +	mode = &drm_enc->crtc->state->adjusted_mode;
> +
>  	priv = drm_enc->dev->dev_private;
>  	dpu_kms = to_dpu_kms(priv->kms);
> 
> @@ -1200,6 +1213,8 @@ static void dpu_encoder_virt_disable(struct
> drm_encoder *drm_enc)
>  	DPU_DEBUG_ENC(dpu_enc, "encoder disabled\n");
> 
>  	dpu_rm_release(&dpu_kms->rm, drm_enc);
> +
> +	mutex_unlock(&dpu_enc->enc_lock);
>  }
> 
>  static enum dpu_intf dpu_encoder_get_intf(struct dpu_mdss_cfg 
> *catalog,
> @@ -2233,6 +2248,8 @@ struct drm_encoder *dpu_encoder_init(struct
> drm_device *dev,
> 
>  	drm_encoder_helper_add(&dpu_enc->base, &dpu_encoder_helper_funcs);
> 
> +	dpu_enc->enabled = false;
> +
>  	return &dpu_enc->base;
>  }

-- 
Jeykumar S
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