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Diffstat (limited to 'Documentation/gpu/todo.rst')
| -rw-r--r-- | Documentation/gpu/todo.rst | 47 |
1 files changed, 11 insertions, 36 deletions
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index be8637da3fe9..b5f58b4274b1 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -173,31 +173,6 @@ Contact: Simona Vetter Level: Intermediate -Get rid of dev->struct_mutex from GEM drivers ---------------------------------------------- - -``dev->struct_mutex`` is the Big DRM Lock from legacy days and infested -everything. Nowadays in modern drivers the only bit where it's mandatory is -serializing GEM buffer object destruction. Which unfortunately means drivers -have to keep track of that lock and either call ``unreference`` or -``unreference_locked`` depending upon context. - -Core GEM doesn't have a need for ``struct_mutex`` any more since kernel 4.8, -and there's a GEM object ``free`` callback for any drivers which are -entirely ``struct_mutex`` free. - -For drivers that need ``struct_mutex`` it should be replaced with a driver- -private lock. The tricky part is the BO free functions, since those can't -reliably take that lock any more. Instead state needs to be protected with -suitable subordinate locks or some cleanup work pushed to a worker thread. For -performance-critical drivers it might also be better to go with a more -fine-grained per-buffer object and per-context lockings scheme. Currently only -the ``msm`` and `i915` drivers use ``struct_mutex``. - -Contact: Simona Vetter, respective driver maintainers - -Level: Advanced - Move Buffer Object Locking to dma_resv_lock() --------------------------------------------- @@ -497,19 +472,19 @@ Contact: Douglas Anderson <dianders@chromium.org> Level: Intermediate -Transition away from using mipi_dsi_*_write_seq() -------------------------------------------------- +Transition away from using deprecated MIPI DSI functions +-------------------------------------------------------- -The macros mipi_dsi_generic_write_seq() and mipi_dsi_dcs_write_seq() are -non-intuitive because, if there are errors, they return out of the *caller's* -function. We should move all callers to use mipi_dsi_generic_write_seq_multi() -and mipi_dsi_dcs_write_seq_multi() macros instead. +There are many functions defined in ``drm_mipi_dsi.c`` which have been +deprecated. Each deprecated function was deprecated in favor of its `multi` +variant (e.g. `mipi_dsi_generic_write()` and `mipi_dsi_generic_write_multi()`). +The `multi` variant of a function includes improved error handling and logic +which makes it more convenient to make several calls in a row, as most MIPI +drivers do. -Once all callers are transitioned, the macros and the functions that they call, -mipi_dsi_generic_write_chatty() and mipi_dsi_dcs_write_buffer_chatty(), can -probably be removed. Alternatively, if people feel like the _multi() variants -are overkill for some use cases, we could keep the mipi_dsi_*_write_seq() -variants but change them not to return out of the caller. +Drivers should be updated to use undeprecated functions. Once all usages of the +deprecated MIPI DSI functions have been removed, their definitions may be +removed from ``drm_mipi_dsi.c``. Contact: Douglas Anderson <dianders@chromium.org> |