Op 14-12-16 om 14:17 schreef Daniel Vetter:
On Wed, Nov 16, 2016 at 02:58:04PM +0100, Maarten Lankhorst wrote:
Second approach. Instead of trying to convert all drivers straight away, implement all macros that are required to get state working.
Current situation: Use obj->state, which can refer to old or new state. Use drm_atomic_get_(existing_)obj_state, which can refer to new or old state. Use for_each_obj_in_state, which refers to new or old state.
New situation: When doing some dereferencing outside atomic_state, use drm_atomic_get_current_obj_state which has locking checks, instead of obj->state.
During atomic check:
- Use drm_atomic_get_obj_state to add a object to the atomic state, or get the new state.
- Use drm_atomic_get_(old/new)_obj_state to peek at the new/old state, without adding the object if it's not part of the state. For planes and connectors the relevant crtc_state is added, so this will work to get the crtc_state from foo_state->crtc too, saves some error handling. :)
During atomic commit:
- Do not use drm_atomic_get_obj_state, obj->state or drm_atomic_get_(existing_)obj_state any more, replace with drm_atomic_get_old/new_obj_state calls as required.
During both:
- Use for_each_(new,old,oldnew)_obj_in_state to get the old or new state as needed. oldnew will be renamed to for_each_obj_in_state after all callers are converted to the new api.
This will give the correct state regardless of swapping.
So this is all nice, but fundamentally it's pile of new code with 0 users. Where are those patches? I think at least converting all the core+helpers to use it consistently would be needed to justify this.
I deliberately didn't send those patches this time because the drivers and atomic core change all the time. I would have had to respin this whole series at least 4 times. :) I have the patches for conversion in my tree based on -tip.
https://cgit.freedesktop.org/~mlankhorst/linux/log/?h=nightly