This patchset adds the callbacks begin_fb_access and end_fb_access
to struct drm_plane_helper_funcs. They provide hooks to acquire and
release resources that are only held during the commit. It adds
related simple-KMS helpers and converts shadow-plane helpers.
As resource allocation often can fail, we have to do this before an
atomic commit starts the update in order to handle the error. But
prepare_fb is only reverted after the next pageflip. We want to
reduce the time resources are held for a commit, which requires the
new hooks.
With this in place, move shadow-plane helpers' automatic vmap/vunmap
behind the new callbacks. The shadow-plane mapping is only required
during the atomic commit.
Tested with combinations of radeon, udl and simpledrm under X11, Weston
and Wayland-Gnome.
Thomas Zimmermann (2):
drm/atomic-helper: Add {begin,end}_fb_access to plane helpers
drm/gem: Implement shadow-plane {begin,end}_fb_access with vmap
drivers/gpu/drm/drm_atomic_helper.c | 34 ++++++++++--
drivers/gpu/drm/drm_gem_atomic_helper.c | 66 +++++++++++-------------
drivers/gpu/drm/drm_simple_kms_helper.c | 26 ++++++++++
include/drm/drm_gem_atomic_helper.h | 20 +++----
include/drm/drm_modeset_helper_vtables.h | 41 ++++++++++++++-
include/drm/drm_simple_kms_helper.h | 20 +++++++
6 files changed, 157 insertions(+), 50 deletions(-)
base-commit: 746559738f1335241ea686566cb654847c20d7a4
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2.38.0
