[PATCH 02/23] drm/atomic-helper: Make drm_atomic_helper_disable_all() update the plane->fb pointers

[Daniel Vetter]

On Thu, Mar 22, 2018 at 05:22:52PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> drm_atomic_helper_shutdown() needs to release the reference held by
> plane->fb, so we want to use drm_atomic_clean_old_fb() in
> drm_atomic_helper_disable_all(). However during suspend/resume, gpu
> reset and load detection we should probably leave that stuff alone,
> as otherwise we'd have to make sure we put them back again when
> we restore the duplicated state to the device. Seems simpler to me
> to not touch any of it anyway.
> 
> v2: Don't inflict the clean_old_fbs bool to drivers (Daniel)
> 
> Cc: martin.peres at free.fr
> Cc: chris at chris-wilson.co.uk
> Cc: Dave Airlie <airlied at gmail.com> (v1)
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

I think this would be cleaner diff to read if you squash the first 2
patches together. Also avoids the bisect fail. With that (and I trust you
to come up with a suitably merged commit message):

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

I reviewed this by re-reading the analysis from 49d70aeaeca8f62b72b77 and
trusting my former self :-)

Cheers, Daniel

> ---
>  drivers/gpu/drm/drm_atomic_helper.c | 67 ++++++++++++++++++++++---------------
>  1 file changed, 40 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index c48f187d08de..39a69508d8c9 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -2881,31 +2881,9 @@ int __drm_atomic_helper_set_config(struct drm_mode_set *set,
>  	return 0;
>  }
>  
> -/**
> - * drm_atomic_helper_disable_all - disable all currently active outputs
> - * @dev: DRM device
> - * @ctx: lock acquisition context
> - *
> - * Loops through all connectors, finding those that aren't turned off and then
> - * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
> - * that they are connected to.
> - *
> - * This is used for example in suspend/resume to disable all currently active
> - * functions when suspending. If you just want to shut down everything at e.g.
> - * driver unload, look at drm_atomic_helper_shutdown().
> - *
> - * Note that if callers haven't already acquired all modeset locks this might
> - * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
> - *
> - * Returns:
> - * 0 on success or a negative error code on failure.
> - *
> - * See also:
> - * drm_atomic_helper_suspend(), drm_atomic_helper_resume() and
> - * drm_atomic_helper_shutdown().
> - */
> -int drm_atomic_helper_disable_all(struct drm_device *dev,
> -				  struct drm_modeset_acquire_ctx *ctx)
> +static int __drm_atomic_helper_disable_all(struct drm_device *dev,
> +					   struct drm_modeset_acquire_ctx *ctx,
> +					   bool clean_old_fbs)
>  {
>  	struct drm_atomic_state *state;
>  	struct drm_connector_state *conn_state;
> @@ -2914,6 +2892,7 @@ int drm_atomic_helper_disable_all(struct drm_device *dev,
>  	struct drm_plane *plane;
>  	struct drm_crtc_state *crtc_state;
>  	struct drm_crtc *crtc;
> +	unsigned int plane_mask = 0;
>  	int ret, i;
>  
>  	state = drm_atomic_state_alloc(dev);
> @@ -2956,14 +2935,48 @@ int drm_atomic_helper_disable_all(struct drm_device *dev,
>  			goto free;
>  
>  		drm_atomic_set_fb_for_plane(plane_state, NULL);
> +
> +		if (clean_old_fbs) {
> +			plane->old_fb = plane->fb;
> +			plane_mask |= BIT(drm_plane_index(plane));
> +		}
>  	}
>  
>  	ret = drm_atomic_commit(state);
>  free:
> +	drm_atomic_clean_old_fb(dev, plane_mask, ret);
> +
>  	drm_atomic_state_put(state);
>  	return ret;
>  }
> -
> +/**
> + * drm_atomic_helper_disable_all - disable all currently active outputs
> + * @dev: DRM device
> + * @ctx: lock acquisition context
> + *
> + * Loops through all connectors, finding those that aren't turned off and then
> + * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
> + * that they are connected to.
> + *
> + * This is used for example in suspend/resume to disable all currently active
> + * functions when suspending. If you just want to shut down everything at e.g.
> + * driver unload, look at drm_atomic_helper_shutdown().
> + *
> + * Note that if callers haven't already acquired all modeset locks this might
> + * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
> + *
> + * Returns:
> + * 0 on success or a negative error code on failure.
> + *
> + * See also:
> + * drm_atomic_helper_suspend(), drm_atomic_helper_resume() and
> + * drm_atomic_helper_shutdown().
> + */
> +int drm_atomic_helper_disable_all(struct drm_device *dev,
> +				  struct drm_modeset_acquire_ctx *ctx)
> +{
> +	return __drm_atomic_helper_disable_all(dev, ctx, false);
> +}
>  EXPORT_SYMBOL(drm_atomic_helper_disable_all);
>  
>  /**
> @@ -2986,7 +2999,7 @@ void drm_atomic_helper_shutdown(struct drm_device *dev)
>  	while (1) {
>  		ret = drm_modeset_lock_all_ctx(dev, &ctx);
>  		if (!ret)
> -			ret = drm_atomic_helper_disable_all(dev, &ctx);
> +			ret = __drm_atomic_helper_disable_all(dev, &ctx, true);
>  
>  		if (ret != -EDEADLK)
>  			break;
> -- 
> 2.16.1
> 

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