Re: [Intel-gfx] [PATCH 2/2] drm/i915/display: throw out struct intel_load_detect_pipe

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Apr 17, 2023 at 06:37:41PM +0300, Jani Nikula wrote:
> An error-valued pointer can handle all in one without the wrapper
> struct.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_crt.c      | 18 ++++++++---------
>  .../gpu/drm/i915/display/intel_load_detect.c  | 20 ++++++++-----------
>  .../gpu/drm/i915/display/intel_load_detect.h  | 12 ++++-------
>  drivers/gpu/drm/i915/display/intel_tv.c       | 16 +++++++--------
>  4 files changed, 29 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_crt.c b/drivers/gpu/drm/i915/display/intel_crt.c
> index 96acdf98a0c0..13519f78cf9f 100644
> --- a/drivers/gpu/drm/i915/display/intel_crt.c
> +++ b/drivers/gpu/drm/i915/display/intel_crt.c
> @@ -822,9 +822,9 @@ intel_crt_detect(struct drm_connector *connector,
>  	struct drm_i915_private *dev_priv = to_i915(connector->dev);
>  	struct intel_crt *crt = intel_attached_crt(to_intel_connector(connector));
>  	struct intel_encoder *intel_encoder = &crt->base;
> +	struct drm_atomic_state *state;
>  	intel_wakeref_t wakeref;
> -	int status, ret;
> -	struct intel_load_detect_pipe tmp;
> +	int status;
>  
>  	drm_dbg_kms(&dev_priv->drm, "[CONNECTOR:%d:%s] force=%d\n",
>  		    connector->base.id, connector->name,
> @@ -882,8 +882,12 @@ intel_crt_detect(struct drm_connector *connector,
>  	}
>  
>  	/* for pre-945g platforms use load detect */
> -	ret = intel_load_detect_get_pipe(connector, &tmp, ctx);
> -	if (ret > 0) {
> +	state = intel_load_detect_get_pipe(connector, ctx);
> +	if (IS_ERR(state)) {
> +		status = PTR_ERR(state);
> +	} else if (!state) {
> +		status = connector_status_unknown;
> +	} else {
>  		if (intel_crt_detect_ddc(connector))
>  			status = connector_status_connected;
>  		else if (DISPLAY_VER(dev_priv) < 4)
> @@ -893,11 +897,7 @@ intel_crt_detect(struct drm_connector *connector,
>  			status = connector_status_disconnected;
>  		else
>  			status = connector_status_unknown;
> -		intel_load_detect_release_pipe(connector, &tmp, ctx);
> -	} else if (ret == 0) {
> -		status = connector_status_unknown;
> -	} else {
> -		status = ret;
> +		intel_load_detect_release_pipe(connector, state, ctx);

I confess it took me a while to see that we have the same logic in place.
I think I need more coffee.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

>  	}
>  
>  out:
> diff --git a/drivers/gpu/drm/i915/display/intel_load_detect.c b/drivers/gpu/drm/i915/display/intel_load_detect.c
> index 5d6bb6d712bc..d5a0aecf3e8f 100644
> --- a/drivers/gpu/drm/i915/display/intel_load_detect.c
> +++ b/drivers/gpu/drm/i915/display/intel_load_detect.c
> @@ -44,9 +44,9 @@ static int intel_modeset_disable_planes(struct drm_atomic_state *state,
>  	return 0;
>  }
>  
> -int intel_load_detect_get_pipe(struct drm_connector *connector,
> -			       struct intel_load_detect_pipe *old,
> -			       struct drm_modeset_acquire_ctx *ctx)
> +struct drm_atomic_state *
> +intel_load_detect_get_pipe(struct drm_connector *connector,
> +			   struct drm_modeset_acquire_ctx *ctx)
>  {
>  	struct intel_encoder *encoder =
>  		intel_attached_encoder(to_intel_connector(connector));
> @@ -64,8 +64,6 @@ int intel_load_detect_get_pipe(struct drm_connector *connector,
>  		    connector->base.id, connector->name,
>  		    encoder->base.base.id, encoder->base.name);
>  
> -	old->restore_state = NULL;
> -
>  	drm_WARN_ON(dev, !drm_modeset_is_locked(&config->connection_mutex));
>  
>  	/*
> @@ -179,13 +177,12 @@ int intel_load_detect_get_pipe(struct drm_connector *connector,
>  		goto fail;
>  	}
>  
> -	old->restore_state = restore_state;
>  	drm_atomic_state_put(state);
>  
>  	/* let the connector get through one full cycle before testing */
>  	intel_crtc_wait_for_next_vblank(crtc);
>  
> -	return true;
> +	return restore_state;
>  
>  fail:
>  	if (state) {
> @@ -198,27 +195,26 @@ int intel_load_detect_get_pipe(struct drm_connector *connector,
>  	}
>  
>  	if (ret == -EDEADLK)
> -		return ret;
> +		return ERR_PTR(ret);
>  
> -	return false;
> +	return NULL;
>  }
>  
>  void intel_load_detect_release_pipe(struct drm_connector *connector,
> -				    struct intel_load_detect_pipe *old,
> +				    struct drm_atomic_state *state,
>  				    struct drm_modeset_acquire_ctx *ctx)
>  {
>  	struct intel_encoder *intel_encoder =
>  		intel_attached_encoder(to_intel_connector(connector));
>  	struct drm_i915_private *i915 = to_i915(intel_encoder->base.dev);
>  	struct drm_encoder *encoder = &intel_encoder->base;
> -	struct drm_atomic_state *state = old->restore_state;
>  	int ret;
>  
>  	drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
>  		    connector->base.id, connector->name,
>  		    encoder->base.id, encoder->name);
>  
> -	if (!state)
> +	if (IS_ERR_OR_NULL(state))
>  		return;
>  
>  	ret = drm_atomic_helper_commit_duplicated_state(state, ctx);
> diff --git a/drivers/gpu/drm/i915/display/intel_load_detect.h b/drivers/gpu/drm/i915/display/intel_load_detect.h
> index 9b69da1867a5..aed51901b9ba 100644
> --- a/drivers/gpu/drm/i915/display/intel_load_detect.h
> +++ b/drivers/gpu/drm/i915/display/intel_load_detect.h
> @@ -10,15 +10,11 @@ struct drm_atomic_state;
>  struct drm_connector;
>  struct drm_modeset_acquire_ctx;
>  
> -struct intel_load_detect_pipe {
> -	struct drm_atomic_state *restore_state;
> -};
> -
> -int intel_load_detect_get_pipe(struct drm_connector *connector,
> -			       struct intel_load_detect_pipe *old,
> -			       struct drm_modeset_acquire_ctx *ctx);
> +struct drm_atomic_state *
> +intel_load_detect_get_pipe(struct drm_connector *connector,
> +			   struct drm_modeset_acquire_ctx *ctx);
>  void intel_load_detect_release_pipe(struct drm_connector *connector,
> -				    struct intel_load_detect_pipe *old,
> +				    struct drm_atomic_state *old,
>  				    struct drm_modeset_acquire_ctx *ctx);
>  
>  #endif /* __INTEL_LOAD_DETECT_H__ */
> diff --git a/drivers/gpu/drm/i915/display/intel_tv.c b/drivers/gpu/drm/i915/display/intel_tv.c
> index 07e7f7cdd961..e3ccface0c9d 100644
> --- a/drivers/gpu/drm/i915/display/intel_tv.c
> +++ b/drivers/gpu/drm/i915/display/intel_tv.c
> @@ -1723,21 +1723,21 @@ intel_tv_detect(struct drm_connector *connector,
>  		return connector_status_disconnected;
>  
>  	if (force) {
> -		struct intel_load_detect_pipe tmp;
> -		int ret;
> +		struct drm_atomic_state *state;
>  
> -		ret = intel_load_detect_get_pipe(connector, &tmp, ctx);
> -		if (ret < 0)
> -			return ret;
> +		state = intel_load_detect_get_pipe(connector, ctx);
> +		if (IS_ERR(state))
> +			return PTR_ERR(state);
>  
> -		if (ret > 0) {
> +		if (state) {
>  			type = intel_tv_detect_type(intel_tv, connector);
> -			intel_load_detect_release_pipe(connector, &tmp, ctx);
> +			intel_load_detect_release_pipe(connector, state, ctx);
>  			status = type < 0 ?
>  				connector_status_disconnected :
>  				connector_status_connected;
> -		} else
> +		} else {
>  			status = connector_status_unknown;
> +		}
>  
>  		if (status == connector_status_connected) {
>  			intel_tv->type = type;
> -- 
> 2.39.2
>