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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2021-01-22 14:36:23 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2021-02-03 14:09:44 +0100 |
| commit | 5823cca39d585e4b4a32b1292eed0015da9c3276 (patch) | |
| tree | f162e3ea9d3041d505480ce7cf110629eae8b78f /Documentation/gpu/todo.rst | |
| parent | 09b20988ff29eecc422484c266bee61b2fe58d8c (diff) | |
| download | linux-5823cca39d585e4b4a32b1292eed0015da9c3276.tar.bz2 | |
drm/todo: Add entry for moving to dma_resv_lock
Requested by Thomas. I think it justifies a new level, since I tried
to make some forward progress on this last summer, and gave up (for
now). This is very tricky.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210122133624.1751802-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'Documentation/gpu/todo.rst')
| -rw-r--r-- | Documentation/gpu/todo.rst | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index dea9082c0e5f..f872d3d33218 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -23,6 +23,9 @@ Advanced: Tricky tasks that need fairly good understanding of the DRM subsystem and graphics topics. Generally need the relevant hardware for development and testing. +Expert: Only attempt these if you've successfully completed some tricky +refactorings already and are an expert in the specific area + Subsystem-wide refactorings =========================== @@ -168,6 +171,22 @@ Contact: Daniel Vetter, respective driver maintainers Level: Advanced +Move Buffer Object Locking to dma_resv_lock() +--------------------------------------------- + +Many drivers have their own per-object locking scheme, usually using +mutex_lock(). This causes all kinds of trouble for buffer sharing, since +depending which driver is the exporter and importer, the locking hierarchy is +reversed. + +To solve this we need one standard per-object locking mechanism, which is +dma_resv_lock(). This lock needs to be called as the outermost lock, with all +other driver specific per-object locks removed. The problem is tha rolling out +the actual change to the locking contract is a flag day, due to struct dma_buf +buffer sharing. + +Level: Expert + Convert logging to drm_* functions with drm_device paramater ------------------------------------------------------------ |