[PATCH 3/9] drm/display/dp_mst: Add drm_atomic_get_old_mst_topology_state()

[Ville Syrjälä]

On Wed, Jan 25, 2023 at 01:48:46PM +0200, Imre Deak wrote:
> Add a function to get the old MST topology state, required by a
> follow-up i915 patch.
> 
> While at it clarify the code comment of
> drm_atomic_get_new_mst_topology_state().
> 
> Cc: Lyude Paul <lyude at redhat.com>
> Cc: stable at vger.kernel.org # 6.1
> Cc: dri-devel at lists.freedesktop.org
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>  drivers/gpu/drm/display/drm_dp_mst_topology.c | 29 +++++++++++++++++--
>  include/drm/display/drm_dp_mst_helper.h       |  3 ++
>  2 files changed, 30 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> index ebf6e31e156e0..81cc0c3b1e000 100644
> --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> @@ -5362,18 +5362,43 @@ struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_a
>  }
>  EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
>  
> +/**
> + * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any
> + * @state: global atomic state
> + * @mgr: MST topology manager, also the private object in this case
> + *
> + * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic
> + * state vtable so that the private object state returned is that of a MST
> + * topology object.
> + *
> + * Returns:
> + *
> + * The old MST topology state, or NULL if there's no topology state for this MST mgr
> + * in the global atomic state
> + */
> +struct drm_dp_mst_topology_state *
> +drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
> +				      struct drm_dp_mst_topology_mgr *mgr)
> +{
> +	struct drm_private_state *priv_state =

I would include 'old_' in the variable name to remind the reader what it
is.

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> +		drm_atomic_get_old_private_obj_state(state, &mgr->base);
> +
> +	return priv_state ? to_dp_mst_topology_state(priv_state) : NULL;
> +}
> +EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state);
> +
>  /**
>   * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any
>   * @state: global atomic state
>   * @mgr: MST topology manager, also the private object in this case
>   *
> - * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
> + * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic
>   * state vtable so that the private object state returned is that of a MST
>   * topology object.
>   *
>   * Returns:
>   *
> - * The MST topology state, or NULL if there's no topology state for this MST mgr
> + * The new MST topology state, or NULL if there's no topology state for this MST mgr
>   * in the global atomic state
>   */
>  struct drm_dp_mst_topology_state *
> diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h
> index f5eb9aa152b14..32c764fb9cb56 100644
> --- a/include/drm/display/drm_dp_mst_helper.h
> +++ b/include/drm/display/drm_dp_mst_helper.h
> @@ -868,6 +868,9 @@ struct drm_dp_mst_topology_state *
>  drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
>  				  struct drm_dp_mst_topology_mgr *mgr);
>  struct drm_dp_mst_topology_state *
> +drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
> +				      struct drm_dp_mst_topology_mgr *mgr);
> +struct drm_dp_mst_topology_state *
>  drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state,
>  				      struct drm_dp_mst_topology_mgr *mgr);
>  struct drm_dp_mst_atomic_payload *
> -- 
> 2.37.1

-- 
Ville Syrjälä
Intel