Add additional information on the semantics of the size fields in struct drm_mode_config. Also add a TODO to review all driver for correct usage of these fields.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de --- Documentation/gpu/todo.rst | 15 +++++++++++++++ include/drm/drm_mode_config.h | 13 +++++++++++++ 2 files changed, 28 insertions(+)
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 60d1d7ee0719..f4e1d72149f7 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -463,6 +463,21 @@ Contact: Thomas Zimmermann tzimmermann@suse.de, Christian König, Daniel Vette
Level: Intermediate
+Review all drivers for setting struct drm_mode_config.{max_width,max_height} correctly +-------------------------------------------------------------------------------------- + +The values in struct drm_mode_config.{max_width,max_height} describe the +maximum supported framebuffer size. It's the virtual screen size, but many +drivers treat it like limitations of the physical resolution. + +The maximum width depends on the hardware's maximum scanline pitch. The +maximum height depends on the amount of addressable video memory. Review all +drivers to initialize the fields to the correct values. + +Contact: Thomas Zimmermann tzimmermann@suse.de + +Level: Intermediate +
Core refactorings ================= diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h index 48b7de80daf5..91ca575a78de 100644 --- a/include/drm/drm_mode_config.h +++ b/include/drm/drm_mode_config.h @@ -359,6 +359,19 @@ struct drm_mode_config_funcs { * Core mode resource tracking structure. All CRTC, encoders, and connectors * enumerated by the driver are added here, as are global properties. Some * global restrictions are also here, e.g. dimension restrictions. + * + * Framebuffer sizes refer to the virtual screen that can be displayed by + * the CRTC. This can be different from the physical resolution programmed. + * The minimum width and height, stored in @min_width and @min_height, + * describe the smallest size of the framebuffer. It correlates to the + * minimum programmable resolution. + * The maximum width, stored in @max_width, is typically limited by the + * maximum pitch between two adjacent scanlines. The maximum height, stored + * in @max_height, is usually only limited by the amount of addressable video + * memory. For hardware that has no real maximum, drivers should pick a + * reasonable default. + * + * See also @DRM_SHADOW_PLANE_MAX_WIDTH and @DRM_SHADOW_PLANE_MAX_HEIGHT. */ struct drm_mode_config { /**