Ast has vmap calls in its cursor's atomic_update function. This is not supported as vmap might aquire the dma reservation lock. While at it, cleanup the whole cursor code: the patchset removes all possible runtime errors from the atomic_update function and reduces the overhead from vmap calls on the HW cursor BOs to a minimum.
Patches 1 to 3 update the cursor code and prepare before the refactoring.
Patch 4 and 5 inline the cursor update logic into the rsp cursor-plane functions. This is mostly about moving code around.
Patches 6 to 8 and 12 add a dedicated cursor plane that maintains the two BOs for HW cursors. The HW cursor BOs are permanently pinned and vmapped while the cursor plane is initialized. Thus removing the related vmap operations from atomic_update.
Patches 9 to 11 moves more vmap code out of atomic_update. BOs with cursor image data from userspace are vmapped and vunmapped in prepare_fb and cleanup_fb. Instead the actual update of the cursor image is moved from prepare_fb to atomic_update.
With the patchset applied, all cursor preparation is performed before the commit-tail functions; while the actual update is performed within.
Tested by running X11 and Weston on ast hardware.
Thomas Zimmermann (12): drm/ast: Add constants for VGACRCB register bits drm/ast: Fix invalid usage of AST_MAX_HWC_WIDTH in cursor atomic_check drm/ast: Initialize planes in helper functions drm/ast: Allocate HW cursor BOs during cursor-plane initialization drm/ast: Inline ast cursor-update functions into modesetting code drm/ast: Add cursor-plane data structure drm/ast: Store cursor BOs in cursor plane drm/ast: Map HW cursor BOs permanently drm/ast: Introduce dedicated cursor-plane state drm/ast: Fix cursor BO pinning and mapping drm/ast: Move all of the cursor-update functionality to atomic_update drm/ast: Store each HW cursor offset after pinning the rsp BO
drivers/gpu/drm/ast/Makefile | 3 +- drivers/gpu/drm/ast/ast_cursor.c | 286 ---------------------- drivers/gpu/drm/ast/ast_drv.h | 47 ++-- drivers/gpu/drm/ast/ast_mode.c | 397 +++++++++++++++++++++++++++---- 4 files changed, 389 insertions(+), 344 deletions(-) delete mode 100644 drivers/gpu/drm/ast/ast_cursor.c
base-commit: 3836b7fdfad40e2bac5dc882332f42bed6942cf4 prerequisite-patch-id: c2b2f08f0eccc9f5df0c0da49fa1d36267deb11d -- 2.30.0