[PATCH 05/14] drm/msm/dpu: enable master-slave encoders explicitly

[Sean Paul]

On Tue, Aug 28, 2018 at 05:39:54PM -0700, Jeykumar Sankaran wrote:
> Identify slave-master encoders during initialization and enable
> the encoders explicitly as the current logic has redundant and
> ambiguous loops.

Please include a "Changes in vX" section so I don't need to figure it out myself.

> 
> Signed-off-by: Jeykumar Sankaran <jsanka at codeaurora.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 46 ++++++++++-------------------
>  1 file changed, 15 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 991b22c..b223bd2 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -180,6 +180,7 @@ struct dpu_encoder_virt {
>  	unsigned int num_phys_encs;
>  	struct dpu_encoder_phys *phys_encs[MAX_PHYS_ENCODERS_PER_VIRTUAL];
>  	struct dpu_encoder_phys *cur_master;
> +	struct dpu_encoder_phys *cur_slave;
>  	struct dpu_hw_pingpong *hw_pp[MAX_CHANNELS_PER_ENC];
>  
>  	bool intfs_swapped;
> @@ -1141,7 +1142,8 @@ void dpu_encoder_virt_restore(struct drm_encoder *drm_enc)
>  static void dpu_encoder_virt_enable(struct drm_encoder *drm_enc)
>  {
>  	struct dpu_encoder_virt *dpu_enc = NULL;
> -	int i, ret = 0;
> +	struct dpu_encoder_phys *phys  = NULL;
> +	int ret = 0;
>  	struct drm_display_mode *cur_mode = NULL;
>  
>  	if (!drm_enc) {
> @@ -1154,21 +1156,14 @@ static void dpu_encoder_virt_enable(struct drm_encoder *drm_enc)
>  	trace_dpu_enc_enable(DRMID(drm_enc), cur_mode->hdisplay,
>  			     cur_mode->vdisplay);
>  
> -	dpu_enc->cur_master = NULL;
> -	for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> -		struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
> +	/* always enable slave encoder before master */
> +	phys = dpu_enc->cur_slave;

I think this variable makes things less readable. It made sense in the loop since
you're indented an extra level and they're obfuscated anyways, but since they're
explicit now, could you please just use dpu_enc->cur_slave/master directly?

With this nit and the added changelog in the commit addressed,

Reviewed-by: Sean Paul <seanpaul at chromium.org>


> +	if (phys && phys->ops.enable)
> +		phys->ops.enable(phys);
>  
> -		if (phys && phys->ops.is_master && phys->ops.is_master(phys)) {
> -			DPU_DEBUG_ENC(dpu_enc, "master is now idx %d\n", i);
> -			dpu_enc->cur_master = phys;
> -			break;
> -		}
> -	}
> -
> -	if (!dpu_enc->cur_master) {
> -		DPU_ERROR("virt encoder has no master! num_phys %d\n", i);
> -		return;
> -	}
> +	phys = dpu_enc->cur_master;
> +	if (phys && phys->ops.enable)
> +		phys->ops.enable(phys);
>  
>  	ret = dpu_encoder_resource_control(drm_enc, DPU_ENC_RC_EVENT_KICKOFF);
>  	if (ret) {
> @@ -1177,21 +1172,6 @@ static void dpu_encoder_virt_enable(struct drm_encoder *drm_enc)
>  		return;
>  	}
>  
> -	for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> -		struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
> -
> -		if (!phys)
> -			continue;
> -
> -		if (phys != dpu_enc->cur_master) {
> -			if (phys->ops.enable)
> -				phys->ops.enable(phys);
> -		}
> -	}
> -
> -	if (dpu_enc->cur_master->ops.enable)
> -		dpu_enc->cur_master->ops.enable(dpu_enc->cur_master);
> -
>  	_dpu_encoder_virt_enable_helper(drm_enc);
>  }
>  
> @@ -2062,6 +2042,11 @@ static int dpu_encoder_virt_add_phys_encs(
>  		++dpu_enc->num_phys_encs;
>  	}
>  
> +	if (params->split_role == ENC_ROLE_SLAVE)
> +		dpu_enc->cur_slave = enc;
> +	else
> +		dpu_enc->cur_master = enc;
> +
>  	return 0;
>  }
>  
> @@ -2228,7 +2213,6 @@ int dpu_encoder_setup(struct drm_device *dev, struct drm_encoder *enc,
>  	if (ret)
>  		goto fail;
>  
> -	dpu_enc->cur_master = NULL;
>  	spin_lock_init(&dpu_enc->enc_spinlock);
>  
>  	atomic_set(&dpu_enc->frame_done_timeout, 0);
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS