[PATCH 8/8] drm/vc4: kms: Convert to atomic helpers

[Thomas Zimmermann]

Am 13.11.20 um 16:29 schrieb Maxime Ripard:
> Now that the semaphore is gone, our atomic_commit implementation is
> basically drm_atomic_helper_commit with a somewhat custom commit_tail,
> the main difference being that we're using wait_for_flip_done instead of
> wait_for_vblanks used in the drm_atomic_helper_commit_tail helper.
> 
> Let's switch to using drm_atomic_helper_commit.
> 
> Signed-off-by: Maxime Ripard <maxime at cerno.tech>

Acked-by: Thomas Zimmermann <tzimmermann at suse.de>

> ---
>   drivers/gpu/drm/vc4/vc4_kms.c | 112 +---------------------------------
>   1 file changed, 3 insertions(+), 109 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
> index 79ab7b8a5e0e..ede5d2b6ac65 100644
> --- a/drivers/gpu/drm/vc4/vc4_kms.c
> +++ b/drivers/gpu/drm/vc4/vc4_kms.c
> @@ -333,8 +333,7 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
>   	}
>   }
>   
> -static void
> -vc4_atomic_complete_commit(struct drm_atomic_state *state)
> +static void vc4_atomic_commit_tail(struct drm_atomic_state *state)
>   {
>   	struct drm_device *dev = state->dev;
>   	struct vc4_dev *vc4 = to_vc4_dev(dev);
> @@ -357,10 +356,6 @@ vc4_atomic_complete_commit(struct drm_atomic_state *state)
>   	if (vc4->hvs->hvs5)
>   		clk_set_min_rate(hvs->core_clk, 500000000);
>   
> -	drm_atomic_helper_wait_for_fences(dev, state, false);
> -
> -	drm_atomic_helper_wait_for_dependencies(state);
> -
>   	old_hvs_state = vc4_hvs_get_old_global_state(state);
>   	if (!old_hvs_state)
>   		return;
> @@ -408,20 +403,8 @@ vc4_atomic_complete_commit(struct drm_atomic_state *state)
>   
>   	drm_atomic_helper_cleanup_planes(dev, state);
>   
> -	drm_atomic_helper_commit_cleanup_done(state);
> -
>   	if (vc4->hvs->hvs5)
>   		clk_set_min_rate(hvs->core_clk, 0);
> -
> -	drm_atomic_state_put(state);
> -}
> -
> -static void commit_work(struct work_struct *work)
> -{
> -	struct drm_atomic_state *state = container_of(work,
> -						      struct drm_atomic_state,
> -						      commit_work);
> -	vc4_atomic_complete_commit(state);
>   }
>   
>   static int vc4_atomic_commit_setup(struct drm_atomic_state *state)
> @@ -454,96 +437,6 @@ static int vc4_atomic_commit_setup(struct drm_atomic_state *state)
>   	return 0;
>   }
>   
> -/**
> - * vc4_atomic_commit - commit validated state object
> - * @dev: DRM device
> - * @state: the driver state object
> - * @nonblock: nonblocking commit
> - *
> - * This function commits a with drm_atomic_helper_check() pre-validated state
> - * object. This can still fail when e.g. the framebuffer reservation fails. For
> - * now this doesn't implement asynchronous commits.
> - *
> - * RETURNS
> - * Zero for success or -errno.
> - */
> -static int vc4_atomic_commit(struct drm_device *dev,
> -			     struct drm_atomic_state *state,
> -			     bool nonblock)
> -{
> -	int ret;
> -
> -	if (state->async_update) {
> -		ret = drm_atomic_helper_prepare_planes(dev, state);
> -		if (ret) {
> -			up(&vc4->async_modeset);
> -			return ret;
> -		}
> -
> -		drm_atomic_helper_async_commit(dev, state);
> -
> -		drm_atomic_helper_cleanup_planes(dev, state);
> -
> -		return 0;
> -	}
> -
> -	/* We know for sure we don't want an async update here. Set
> -	 * state->legacy_cursor_update to false to prevent
> -	 * drm_atomic_helper_setup_commit() from auto-completing
> -	 * commit->flip_done.
> -	 */
> -	state->legacy_cursor_update = false;
> -	ret = drm_atomic_helper_setup_commit(state, nonblock);
> -	if (ret)
> -		return ret;
> -
> -	INIT_WORK(&state->commit_work, commit_work);
> -
> -	ret = drm_atomic_helper_prepare_planes(dev, state);
> -	if (ret)
> -		return ret;
> -
> -	if (!nonblock) {
> -		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
> -		if (ret) {
> -			drm_atomic_helper_cleanup_planes(dev, state);
> -			return ret;
> -		}
> -	}
> -
> -	/*
> -	 * This is the point of no return - everything below never fails except
> -	 * when the hw goes bonghits. Which means we can commit the new state on
> -	 * the software side now.
> -	 */
> -
> -	BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
> -
> -	/*
> -	 * Everything below can be run asynchronously without the need to grab
> -	 * any modeset locks at all under one condition: It must be guaranteed
> -	 * that the asynchronous work has either been cancelled (if the driver
> -	 * supports it, which at least requires that the framebuffers get
> -	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
> -	 * before the new state gets committed on the software side with
> -	 * drm_atomic_helper_swap_state().
> -	 *
> -	 * This scheme allows new atomic state updates to be prepared and
> -	 * checked in parallel to the asynchronous completion of the previous
> -	 * update. Which is important since compositors need to figure out the
> -	 * composition of the next frame right after having submitted the
> -	 * current layout.
> -	 */
> -
> -	drm_atomic_state_get(state);
> -	if (nonblock)
> -		queue_work(system_unbound_wq, &state->commit_work);
> -	else
> -		vc4_atomic_complete_commit(state);
> -
> -	return 0;
> -}
> -
>   static struct drm_framebuffer *vc4_fb_create(struct drm_device *dev,
>   					     struct drm_file *file_priv,
>   					     const struct drm_mode_fb_cmd2 *mode_cmd)
> @@ -966,11 +859,12 @@ vc4_atomic_check(struct drm_device *dev, struct drm_atomic_state *state)
>   
>   static struct drm_mode_config_helper_funcs vc4_mode_config_helpers = {
>   	.atomic_commit_setup	= vc4_atomic_commit_setup,
> +	.atomic_commit_tail	= vc4_atomic_commit_tail,
>   };
>   
>   static const struct drm_mode_config_funcs vc4_mode_funcs = {
>   	.atomic_check = vc4_atomic_check,
> -	.atomic_commit = vc4_atomic_commit,
> +	.atomic_commit = drm_atomic_helper_commit,
>   	.fb_create = vc4_fb_create,
>   };
>   
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
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