Am 06.12.24 um 14:12 schrieb Maíra Canal:
This series introduces a series of clean-ups in BO reservations for the VC4 driver. Currently, VC4 uses shared fences to track BO reservations as several other DRM devices. But apart from the DMA reservation objects, VC4 also attaches seqnos to its BOs with the intention to track if the job that uses such BO has finished. The seqno tracking system was introduced before the DMA reservation objects and we ended up lefting it in the code after DMA resv was introduced. This is redundant, as we can perfectly track the end of a job with a fence. Therefore, this series focuses on eliminating the seqnos from the BO. This series introduces a series of clean-ups for BO reservations in the VC4 driver. Currently, VC4 uses shared fences to track BO reservations, similar to many other DRM devices. However, in addition to DMA reservation objects, VC4 has been maintaining a separate seqno tracking system for BOs to track job completion. The seqno tracking system was implemented before DMA reservation objects and was left in the code after DMA reservation's introduction. This approach is now redundant, as job completion can be effectively tracked using fences. Consequently, this series focuses on eliminating seqnos from the BO implementation.
Just FYI, you duplicated the text somehow :)
Patch Breakdown =============== * Patch #1: Uses the DRM GEM implementation of `drm_gem_lock_reservations()` and `drm_gem_unlock_reservations()` to replace the open-coded implementation of this functions by VC4. A straightforward change with no functional changes.
I actually pushed to remove drm_gem_lock_reservations() in favor of using the drm_exec object.
It would be nice if you could use that one instead. Regards, Christian.
* Patch #2: Implements the VC4 wait BO IOCTL using DMA reservations. The new implementation closely mirrors the V3D approach and removes the IOCTL's dependency on BO sequence numbers. * Patch #3: The central piece of this patchset. It removes `bo->seqno`, `bo->write_seqno`, and `exec->bin_dep_seqno` from the driver. As the seqno tracking system is redundant, its deletion is relatively straightforward. The only notable change is `vc4_async_set_fence_cb()`, which now uses `dma_fence_add_callback()` to add the VC4 callback. * Patch #4: Deletes the now-unused function `vc4_queue_seqno_cb()`. Best Regards, - Maíra Maíra Canal (4): drm/vc4: Use `drm_gem_lock_reservations()` instead of hard-coding drm/vc4: Use DMA Resv to implement VC4 wait BO IOCTL drm/vc4: Remove BOs seqnos drm/vc4: Remove `vc4_queue_seqno_cb()` drivers/gpu/drm/vc4/vc4_crtc.c | 22 ++--- drivers/gpu/drm/vc4/vc4_drv.h | 26 ++--- drivers/gpu/drm/vc4/vc4_gem.c | 147 ++++++----------------------- drivers/gpu/drm/vc4/vc4_validate.c | 11 --- 4 files changed, 48 insertions(+), 158 deletions(-)
