Re: [PATCH 01/29] drm/atomic-helper: Fix commit_tail state variable name

[Dmitry Baryshkov]

On Wed, Jan 15, 2025 at 10:05:08PM +0100, Maxime Ripard wrote:
> Even though the commit_tail () drm_atomic_state parameter is called
> old_state, it's actually the state being committed which is confusing.
> 
> It's even more confusing since the atomic_commit_tail hook being called
> by commit_tail() parameter is called state.

Do you have any kind of history and/or explanation, why it's called
old_state all over the place?

I think that the renaming is correct, but I'd like to understand the
reason behind it.

> Let's rename the variable from old_state to state to make it less
> confusing.
> 
> Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/drm_atomic_helper.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 40e4e1b6c9110677c1c4981eeb15dc93966f4cf6..913d94d664d885323ad7e41a6424633c28c787e1 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -1818,13 +1818,13 @@ void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state)
>  
>  	drm_atomic_helper_cleanup_planes(dev, old_state);
>  }
>  EXPORT_SYMBOL(drm_atomic_helper_commit_tail_rpm);
>  
> -static void commit_tail(struct drm_atomic_state *old_state)
> +static void commit_tail(struct drm_atomic_state *state)
>  {
> -	struct drm_device *dev = old_state->dev;
> +	struct drm_device *dev = state->dev;
>  	const struct drm_mode_config_helper_funcs *funcs;
>  	struct drm_crtc_state *new_crtc_state;
>  	struct drm_crtc *crtc;
>  	ktime_t start;
>  	s64 commit_time_ms;
> @@ -1842,37 +1842,37 @@ static void commit_tail(struct drm_atomic_state *old_state)
>  	 * These times will be averaged out in the self refresh helpers to avoid
>  	 * overreacting over one outlier frame
>  	 */
>  	start = ktime_get();
>  
> -	drm_atomic_helper_wait_for_fences(dev, old_state, false);
> +	drm_atomic_helper_wait_for_fences(dev, state, false);
>  
> -	drm_atomic_helper_wait_for_dependencies(old_state);
> +	drm_atomic_helper_wait_for_dependencies(state);
>  
>  	/*
>  	 * We cannot safely access new_crtc_state after
>  	 * drm_atomic_helper_commit_hw_done() so figure out which crtc's have
>  	 * self-refresh active beforehand:
>  	 */
> -	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i)
> +	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i)
>  		if (new_crtc_state->self_refresh_active)
>  			new_self_refresh_mask |= BIT(i);
>  
>  	if (funcs && funcs->atomic_commit_tail)
> -		funcs->atomic_commit_tail(old_state);
> +		funcs->atomic_commit_tail(state);
>  	else
> -		drm_atomic_helper_commit_tail(old_state);
> +		drm_atomic_helper_commit_tail(state);
>  
>  	commit_time_ms = ktime_ms_delta(ktime_get(), start);
>  	if (commit_time_ms > 0)
> -		drm_self_refresh_helper_update_avg_times(old_state,
> +		drm_self_refresh_helper_update_avg_times(state,
>  						 (unsigned long)commit_time_ms,
>  						 new_self_refresh_mask);
>  
> -	drm_atomic_helper_commit_cleanup_done(old_state);
> +	drm_atomic_helper_commit_cleanup_done(state);
>  
> -	drm_atomic_state_put(old_state);
> +	drm_atomic_state_put(state);
>  }
>  
>  static void commit_work(struct work_struct *work)
>  {
>  	struct drm_atomic_state *state = container_of(work,
> 
> -- 
> 2.47.1
> 

-- 
With best wishes
Dmitry