Link bandwidth is a shared resource between multiple displays in DP MST configurations. For atomic modesetting drivers, checking if there is sufficient link bandwidth for a mode needs to be done during the atomic_check phase to avoid failed modesets when multiple CRTC's and connectors are involved.
Managing shared resources like DP MST link bandwidth in the driver's subclassed atomic_state will result in duplicating the code in each atomic modesetting driver. But adding objects like DP MST link bandwidth to the DRM core's drm_atomic_state would mean that an object that is not a core modesetting object like connector, CRTC or a plane will be modified by the helper functions for swapping and clearing state. So, this series introduces void * type driver-private objects in drm_atomic_state and adds helper functions that operate on these private objects. Drivers can then implement object-specific functions to swap and clear states. The advantage of having void * for these objects in drm_atomic_state is that objects of different types can be managed in the same state array.
This version 1) splits and squashes patches 2) adds documentation 3) fixes vcpi slot accounting logic for suspend-resume and connector switching
Dhinakaran Pandiyan (8): drm/dp: Kill total_pbn and total_slots in struct drm_dp_mst_topology_mgr drm/dp: Kill unused MST vcpi slot availability tracking drm/dp: Split drm_dp_mst_allocate_vcpi drm: Add driver-private objects to atomic state drm/dp: Introduce MST topology state to track available link bandwidth drm/dp: Add DP MST helpers to atomically find and release vcpi slots drm: Connector helper function to release resources drm/dp: Track MST link bandwidth
drivers/gpu/drm/drm_atomic.c | 68 ++++++++++++ drivers/gpu/drm/drm_atomic_helper.c | 24 ++++ drivers/gpu/drm/drm_dp_mst_topology.c | 181 ++++++++++++++++++++++++++++--- drivers/gpu/drm/i915/intel_dp_mst.c | 42 +++++-- drivers/gpu/drm/nouveau/nv50_display.c | 3 +- drivers/gpu/drm/radeon/radeon_dp_mst.c | 4 +- include/drm/drm_atomic.h | 91 ++++++++++++++++ include/drm/drm_dp_mst_helper.h | 33 ++++-- include/drm/drm_modeset_helper_vtables.h | 13 +++ 9 files changed, 421 insertions(+), 38 deletions(-)