On Tue, Jun 7, 2022 at 3:06 AM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote: > > Quoting Hsin-Yi Wang (2022-06-06 08:24:24) > > diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c > > index f634371c717a..e12056cfeca8 100644 > > --- a/drivers/gpu/drm/drm_panel.c > > +++ b/drivers/gpu/drm/drm_panel.c > > @@ -223,6 +223,15 @@ int drm_panel_get_modes(struct drm_panel *panel, > > } > > EXPORT_SYMBOL(drm_panel_get_modes); > > > > +enum drm_panel_orientation drm_panel_get_orientation(struct drm_panel *panel) > > Should 'panel' be marked const to indicate that it can't be modified? > But .get_orientation() will need to call to_XXX_panel, eg. static inline struct boe_panel *to_boe_panel(struct drm_panel *panel) ==> .get_modes(panel) <-- can't be const. ==> drm_panel_get_orientation(panel) <-- can't be const. We can definitely cast it in the functions, or make to_XXX_panel() accept const, but I think this will lose the meaning of using const anyway. > > +{ > > + if (panel && panel->funcs && panel->funcs->get_orientation) > > + return panel->funcs->get_orientation(panel);