Re: [PATCH v2 6/9] drm/fbdev-helper: Update documentation on obsolete callbacks

[Daniel Vetter <daniel.vetter@ffwll.ch>]

On Mon, Aug 12, 2024 at 10:28:27AM +0200, Thomas Zimmermann wrote:
> The old callbacks lastclose and output_poll_changed are deprecated and
> unused. Remove them from the documentation.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

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

> ---
>  drivers/gpu/drm/drm_fb_helper.c | 22 +++++++---------------
>  1 file changed, 7 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 3f7da78849e4..fe5667477839 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -89,14 +89,6 @@ static DEFINE_MUTEX(kernel_fb_helper_lock);
>   * interfaces. Drivers that use one of the shared memory managers, TTM, SHMEM,
>   * DMA, should instead use the corresponding fbdev emulation.
>   *
> - * Existing fbdev implementations should restore the fbdev console by using
> - * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.
> - * They should also notify the fb helper code from updates to the output
> - * configuration by using drm_fb_helper_output_poll_changed() as their
> - * &drm_mode_config_funcs.output_poll_changed callback. New implementations
> - * of fbdev should be build on top of struct &drm_client_funcs, which handles
> - * this automatically. Setting the old callbacks should be avoided.
> - *
>   * For suspend/resume consider using drm_mode_config_helper_suspend() and
>   * drm_mode_config_helper_resume() which takes care of fbdev as well.
>   *
> @@ -260,12 +252,12 @@ __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
>   * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
>   * @fb_helper: driver-allocated fbdev helper, can be NULL
>   *
> - * This should be called from driver's drm &drm_driver.lastclose callback
> - * when implementing an fbcon on top of kms using this helper. This ensures that
> - * the user isn't greeted with a black screen when e.g. X dies.
> + * This helper should be called from fbdev emulation's &drm_client_funcs.restore
> + * callback. It ensures that the user isn't greeted with a black screen when the
> + * userspace compositor releases the display device.
>   *
> - * RETURNS:
> - * Zero if everything went ok, negative error code otherwise.
> + * Returns:
> + * 0 on success, or a negative errno code otherwise.
>   */
>  int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
>  {
> @@ -2003,8 +1995,8 @@ EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
>   * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
>   * @dev: DRM device
>   *
> - * This function can be used as the &drm_driver->lastclose callback for drivers
> - * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
> + * This function is obsolete. Call drm_fb_helper_restore_fbdev_mode_unlocked()
> + * instead.
>   */
>  void drm_fb_helper_lastclose(struct drm_device *dev)
>  {
> -- 
> 2.46.0
> 

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