[PATCH v1 11/12] drm/bridge: Drop drm_bridge_funcs.mode_fixup

[Dave Stevenson]

On Sun, 17 Jul 2022 at 18:58, Sam Ravnborg <sam at ravnborg.org> wrote:
>
> All users are converted over to drm_bridge_funcs.atomic_check()
> so it is safe to drop the mode_fixup support.
>
> Update the comment for atomic_check with relevant parts from mode_fixup.
>
> Signed-off-by: Sam Ravnborg <sam at ravnborg.org>

Reviewed-by: Dave Stevenson <dave.stevenson at raspberrypi.com>

> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: David Airlie <airlied at linux.ie>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> ---
>  drivers/gpu/drm/drm_bridge.c |  7 +----
>  include/drm/drm_bridge.h     | 60 ++++++++++--------------------------
>  2 files changed, 17 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index b6f56d8f3547..3f5acb19957c 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -685,10 +685,6 @@ static int drm_atomic_bridge_check(struct drm_bridge *bridge,
>                                                   crtc_state, conn_state);
>                 if (ret)
>                         return ret;
> -       } else if (bridge->funcs->mode_fixup) {
> -               if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,
> -                                              &crtc_state->adjusted_mode))
> -                       return -EINVAL;
>         }
>
>         return 0;
> @@ -934,8 +930,7 @@ drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge,
>   * @conn_state: new connector state
>   *
>   * First trigger a bus format negotiation before calling
> - * &drm_bridge_funcs.atomic_check() (falls back on
> - * &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
> + * &drm_bridge_funcs.atomic_check() op for all the bridges in the encoder chain,
>   * starting from the last bridge to the first. These are called before calling
>   * &drm_encoder_helper_funcs.atomic_check()
>   *
> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> index 7496f41535b1..8c93369bcc74 100644
> --- a/include/drm/drm_bridge.h
> +++ b/include/drm/drm_bridge.h
> @@ -106,7 +106,7 @@ struct drm_bridge_funcs {
>          * to look at anything else but the passed-in mode, and validate it
>          * against configuration-invariant hardward constraints. Any further
>          * limits which depend upon the configuration can only be checked in
> -        * @mode_fixup.
> +        * @atomic_check.
>          *
>          * RETURNS:
>          *
> @@ -116,46 +116,6 @@ struct drm_bridge_funcs {
>                                            const struct drm_display_info *info,
>                                            const struct drm_display_mode *mode);
>
> -       /**
> -        * @mode_fixup:
> -        *
> -        * This callback is used to validate and adjust a mode. The parameter
> -        * mode is the display mode that should be fed to the next element in
> -        * the display chain, either the final &drm_connector or the next
> -        * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
> -        * requires. It can be modified by this callback and does not need to
> -        * match mode. See also &drm_crtc_state.adjusted_mode for more details.
> -        *
> -        * This is the only hook that allows a bridge to reject a modeset. If
> -        * this function passes all other callbacks must succeed for this
> -        * configuration.
> -        *
> -        * The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()
> -        * is not called when &drm_bridge_funcs.atomic_check() is implemented,
> -        * so only one of them should be provided.
> -        *
> -        * NOTE:
> -        *
> -        * This function is called in the check phase of atomic modesets, which
> -        * can be aborted for any reason (including on userspace's request to
> -        * just check whether a configuration would be possible). Drivers MUST
> -        * NOT touch any persistent state (hardware or software) or data
> -        * structures except the passed in @state parameter.
> -        *
> -        * Also beware that userspace can request its own custom modes, neither
> -        * core nor helpers filter modes to the list of probe modes reported by
> -        * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> -        * that modes are filtered consistently put any bridge constraints and
> -        * limits checks into @mode_valid.
> -        *
> -        * RETURNS:
> -        *
> -        * True if an acceptable configuration is possible, false if the modeset
> -        * operation should be rejected.
> -        */
> -       bool (*mode_fixup)(struct drm_bridge *bridge,
> -                          const struct drm_display_mode *mode,
> -                          struct drm_display_mode *adjusted_mode);
>         /**
>          * @disable:
>          *
> @@ -466,9 +426,7 @@ struct drm_bridge_funcs {
>          * &drm_bridge_funcs.atomic_check() hooks are called in reverse
>          * order (from the last to the first bridge).
>          *
> -        * This method is optional. &drm_bridge_funcs.mode_fixup() is not
> -        * called when &drm_bridge_funcs.atomic_check() is implemented, so only
> -        * one of them should be provided.
> +        * This method is optional.
>          *
>          * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
>          * &drm_bridge_state.output_bus_cfg.flags it should happen in
> @@ -478,6 +436,20 @@ struct drm_bridge_funcs {
>          * &drm_connector.display_info.bus_flags if the bridge is the last
>          * element in the chain.
>          *
> +        * NOTE:
> +        *
> +        * This function is called in the check phase of atomic modesets, which
> +        * can be aborted for any reason (including on userspace's request to
> +        * just check whether a configuration would be possible). Drivers MUST
> +        * NOT touch any persistent state (hardware or software) or data
> +        * structures except the passed in @state parameter.
> +        *
> +        * Also beware that userspace can request its own custom modes, neither
> +        * core nor helpers filter modes to the list of probe modes reported by
> +        * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> +        * that modes are filtered consistently put any bridge constraints and
> +        * limits checks into @mode_valid.
> +        *
>          * RETURNS:
>          * zero if the check passed, a negative error code otherwise.
>          */
> --
> 2.34.1
>