Re: [PATCH 6/6] drm/vc4: kms: Add functions to create the state objects

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, Oct 29, 2020 at 08:01:04PM +0100, Maxime Ripard wrote:
> In order to make the vc4_kms_load code and error path a bit easier to
> read and extend, add functions to create state objects, and use managed
> actions to cleanup if needed.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Nice. With an s/drmm_add_action/drmm_add_action_or_reset/ over the entire
series:

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

btw there's a series pending from imx people (Philip Zabel iirc) to add
drmm support for modeset objects. I think that would really help clean up
vc4. Or well make it slightly less buggy, since atm you're using
devm_kzalloc, which strictly speaking, frees the memory too early.

Anyway this here looks all nice.
-Daniel

> ---
>  drivers/gpu/drm/vc4/vc4_drv.c |  3 --
>  drivers/gpu/drm/vc4/vc4_kms.c | 78 +++++++++++++++++++++++++----------
>  2 files changed, 57 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
> index 6e037fbaa090..08c1cc225045 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.c
> +++ b/drivers/gpu/drm/vc4/vc4_drv.c
> @@ -312,9 +312,6 @@ static void vc4_drm_unbind(struct device *dev)
>  	drm_dev_unregister(drm);
>  
>  	drm_atomic_helper_shutdown(drm);
> -
> -	drm_atomic_private_obj_fini(&vc4->load_tracker);
> -	drm_atomic_private_obj_fini(&vc4->ctm_manager);
>  }
>  
>  static const struct component_master_ops vc4_drm_ops = {
> diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
> index 708099a24406..fbfb0698073e 100644
> --- a/drivers/gpu/drm/vc4/vc4_kms.c
> +++ b/drivers/gpu/drm/vc4/vc4_kms.c
> @@ -93,6 +93,29 @@ static const struct drm_private_state_funcs vc4_ctm_state_funcs = {
>  	.atomic_destroy_state = vc4_ctm_destroy_state,
>  };
>  
> +static void vc4_ctm_obj_fini(struct drm_device *dev, void *unused)
> +{
> +	struct vc4_dev *vc4 = to_vc4_dev(dev);
> +
> +	drm_atomic_private_obj_fini(&vc4->ctm_manager);
> +}
> +
> +static int vc4_ctm_obj_init(struct vc4_dev *vc4)
> +{
> +	struct vc4_ctm_state *ctm_state;
> +
> +	drm_modeset_lock_init(&vc4->ctm_state_lock);
> +
> +	ctm_state = kzalloc(sizeof(*ctm_state), GFP_KERNEL);
> +	if (!ctm_state)
> +		return -ENOMEM;
> +
> +	drm_atomic_private_obj_init(vc4->dev, &vc4->ctm_manager, &ctm_state->base,
> +				    &vc4_ctm_state_funcs);
> +
> +	return drmm_add_action(&vc4->base, vc4_ctm_obj_fini, NULL);
> +}
> +
>  /* Converts a DRM S31.32 value to the HW S0.9 format. */
>  static u16 vc4_ctm_s31_32_to_s0_9(u64 in)
>  {
> @@ -609,6 +632,34 @@ static const struct drm_private_state_funcs vc4_load_tracker_state_funcs = {
>  	.atomic_destroy_state = vc4_load_tracker_destroy_state,
>  };
>  
> +static void vc4_load_tracker_obj_fini(struct drm_device *dev, void *unused)
> +{
> +	struct vc4_dev *vc4 = to_vc4_dev(dev);
> +
> +	if (!vc4->load_tracker_available)
> +		return 0;
> +
> +	drm_atomic_private_obj_fini(&vc4->load_tracker);
> +}
> +
> +static int vc4_load_tracker_obj_init(struct vc4_dev *vc4)
> +{
> +	struct vc4_load_tracker_state *load_state;
> +
> +	if (!vc4->load_tracker_available)
> +		return 0;
> +
> +	load_state = kzalloc(sizeof(*load_state), GFP_KERNEL);
> +	if (!load_state)
> +		return -ENOMEM;
> +
> +	drm_atomic_private_obj_init(vc4->dev, &vc4->load_tracker,
> +				    &load_state->base,
> +				    &vc4_load_tracker_state_funcs);
> +
> +	return drmm_add_action(&vc4->base, vc4_load_tracker_obj_fini, NULL);
> +}
> +
>  #define NUM_OUTPUTS  6
>  #define NUM_CHANNELS 3
>  
> @@ -711,8 +762,6 @@ static const struct drm_mode_config_funcs vc4_mode_funcs = {
>  int vc4_kms_load(struct drm_device *dev)
>  {
>  	struct vc4_dev *vc4 = to_vc4_dev(dev);
> -	struct vc4_ctm_state *ctm_state;
> -	struct vc4_load_tracker_state *load_state;
>  	bool is_vc5 = of_device_is_compatible(dev->dev->of_node,
>  					      "brcm,bcm2711-vc5");
>  	int ret;
> @@ -751,26 +800,13 @@ int vc4_kms_load(struct drm_device *dev)
>  	dev->mode_config.async_page_flip = true;
>  	dev->mode_config.allow_fb_modifiers = true;
>  
> -	drm_modeset_lock_init(&vc4->ctm_state_lock);
> +	ret = vc4_ctm_obj_init(vc4);
> +	if (ret)
> +		return ret;
>  
> -	ctm_state = kzalloc(sizeof(*ctm_state), GFP_KERNEL);
> -	if (!ctm_state)
> -		return -ENOMEM;
> -
> -	drm_atomic_private_obj_init(dev, &vc4->ctm_manager, &ctm_state->base,
> -				    &vc4_ctm_state_funcs);
> -
> -	if (vc4->load_tracker_available) {
> -		load_state = kzalloc(sizeof(*load_state), GFP_KERNEL);
> -		if (!load_state) {
> -			drm_atomic_private_obj_fini(&vc4->ctm_manager);
> -			return -ENOMEM;
> -		}
> -
> -		drm_atomic_private_obj_init(dev, &vc4->load_tracker,
> -					    &load_state->base,
> -					    &vc4_load_tracker_state_funcs);
> -	}
> +	ret = vc4_load_tracker_obj_init(vc4);
> +	if (ret)
> +		return ret;
>  
>  	drm_mode_config_reset(dev);
>  
> -- 
> 2.26.2
> 
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> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

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