[PATCH v3 7/7] drm/todo: Update entries around struct dma_buf_map

Thomas Zimmermann tzimmermann at suse.de
Tue Sep 29 11:14:37 EDT 2020


Instances of struct dma_buf_map should be useful throughout DRM's
memory management code. Furthermore, several drivers can now use
generic fbdev emulation.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 Documentation/gpu/todo.rst | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 3751ac976c3e..023626c1837b 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -197,8 +197,10 @@ Convert drivers to use drm_fbdev_generic_setup()
 ------------------------------------------------
 
 Most drivers can use drm_fbdev_generic_setup(). Driver have to implement
-atomic modesetting and GEM vmap support. Current generic fbdev emulation
-expects the framebuffer in system memory (or system-like memory).
+atomic modesetting and GEM vmap support. Historically, generic fbdev emulation
+expected the framebuffer in system memory or system-like memory. By employing
+struct dma_buf_map, drivers with frambuffers in I/O memory can be supported
+as well.
 
 Contact: Maintainer of the driver you plan to convert
 
@@ -446,6 +448,24 @@ Contact: Ville Syrjälä, Daniel Vetter
 
 Level: Intermediate
 
+Use struct dma_buf_map throughout codebase
+------------------------------------------
+
+Pointers to shared device memory are stored in struct dma_buf_map. Each
+instance knows whether it refers to system or I/O memory. Most of the DRM-wide
+interface have been converted to use struct dma_buf_map, but implementations
+often still use raw pointers.
+
+The task is to use struct dma_buf_map where it makes sense.
+
+* Memory managers should use struct dma_buf_map for dma-buf-imported buffers.
+* TTM might benefit from using struct dma_buf_map internally.
+* Framebuffer copying and blitting helpers should operate on struct dma_buf_map.
+
+Contact: Thomas Zimmermann <tzimmermann at suse.de>, Christian König, Daniel Vetter
+
+Level: Intermediate
+
 
 Core refactorings
 =================
-- 
2.28.0




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