On Thu, Mar 06, 2025 at 03:05:46PM +0100, Thomas Zimmermann wrote: > Look at the blank state provided by FB_EVENT_BLANK to determine > whether to enable or disable a backlight. Remove the tracking fields > from struct backlight_device. > > Tracking requires three variables, fb_on, prev_fb_on and the > backlight's use_count. If fb_on is true, the display has been > unblanked. The backlight needs to be enabled if the display was > blanked before (i.e., prev_fb_on is false) or if use_count is still > at 0. If fb_on is false, the display has been blanked. In this case, > the backlight has to be disabled was unblanked before and the > backlight's use_count is greater than 0. > > This change removes fbdev state tracking from blacklight. All the > backlight requires it its own use counter and information about > changes to the display. Removing fbdev internals makes backlight > drivers easier to integrate into other display drivers, such as DRM. > > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Reviewed-by: Daniel Thompson (RISCstar) <danielt@xxxxxxxxxx> Daniel.
