diff options
Diffstat (limited to 'Documentation/gpu/todo.rst')
-rw-r--r-- | Documentation/gpu/todo.rst | 77 |
1 files changed, 55 insertions, 22 deletions
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 68bdafa0284f..03fe5d1247be 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -49,14 +49,18 @@ converted over. Modern compositors like Wayland or Surfaceflinger on Android really want an atomic modeset interface, so this is all about the bright future. -There is a conversion guide for atomic and all you need is a GPU for a -non-converted driver (again virtual HW drivers for KVM are still all -suitable). +There is a conversion guide for atomic [1]_ and all you need is a GPU for a +non-converted driver. The "Atomic mode setting design overview" series [2]_ +[3]_ at LWN.net can also be helpful. As part of this drivers also need to convert to universal plane (which means exposing primary & cursor as proper plane objects). But that's much easier to do by directly using the new atomic helper driver callbacks. + .. [1] https://blog.ffwll.ch/2014/11/atomic-modeset-support-for-kms-drivers.html + .. [2] https://lwn.net/Articles/653071/ + .. [3] https://lwn.net/Articles/653466/ + Contact: Daniel Vetter, respective driver maintainers Level: Advanced @@ -65,7 +69,7 @@ Clean up the clipped coordination confusion around planes --------------------------------------------------------- We have a helper to get this right with drm_plane_helper_check_update(), but -it's not consistently used. This should be fixed, preferrably in the atomic +it's not consistently used. This should be fixed, preferably in the atomic helpers (and drivers then moved over to clipped coordinates). Probably the helper should also be moved from drm_plane_helper.c to the atomic helpers, to avoid confusion - the other helpers in that file are all deprecated legacy @@ -181,13 +185,13 @@ 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 +other driver specific per-object locks removed. The problem is that 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 +Convert logging to drm_* functions with drm_device parameter ------------------------------------------------------------ For drivers which could have multiple instances, it is necessary to @@ -244,7 +248,7 @@ Level: Advanced Benchmark and optimize blitting and format-conversion function -------------------------------------------------------------- -Drawing to dispay memory quickly is crucial for many applications' +Drawing to display memory quickly is crucial for many applications' performance. On at least x86-64, sys_imageblit() is significantly slower than @@ -319,15 +323,6 @@ Contact: Daniel Vetter, Noralf Tronnes Level: Advanced -struct drm_gem_object_funcs ---------------------------- - -GEM objects can now have a function table instead of having the callbacks on the -DRM driver struct. This is now the preferred way. Callbacks in drivers have been -converted, except for struct drm_driver.gem_prime_mmap. - -Level: Intermediate - connector register/unregister fixes ----------------------------------- @@ -452,6 +447,44 @@ Contact: Thomas Zimmermann <tzimmermann@suse.de> Level: Starter +Remove driver dependencies on FB_DEVICE +--------------------------------------- + +A number of fbdev drivers provide attributes via sysfs and therefore depend +on CONFIG_FB_DEVICE to be selected. Review each driver and attempt to make +any dependencies on CONFIG_FB_DEVICE optional. At the minimum, the respective +code in the driver could be conditionalized via ifdef CONFIG_FB_DEVICE. Not +all drivers might be able to drop CONFIG_FB_DEVICE. + +Contact: Thomas Zimmermann <tzimmermann@suse.de> + +Level: Starter + +Clean up checks for already prepared/enabled in panels +------------------------------------------------------ + +In a whole pile of panel drivers, we have code to make the +prepare/unprepare/enable/disable callbacks behave as no-ops if they've already +been called. To get some idea of the duplicated code, try:: + + git grep 'if.*>prepared' -- drivers/gpu/drm/panel + git grep 'if.*>enabled' -- drivers/gpu/drm/panel + +In the patch ("drm/panel: Check for already prepared/enabled in drm_panel") +we've moved this check to the core. Now we can most definitely remove the +check from the individual panels and save a pile of code. + +In adition to removing the check from the individual panels, it is believed +that even the core shouldn't need this check and that should be considered +an error if other code ever relies on this check. The check in the core +currently prints a warning whenever something is relying on this check with +dev_warn(). After a little while, we likely want to promote this to a +WARN(1) to help encourage folks not to rely on this behavior. + +Contact: Douglas Anderson <dianders@chromium.org> + +Level: Starter/Intermediate + Core refactorings ================= @@ -749,16 +782,16 @@ existing hardware. The new driver's call-back functions are filled from existing fbdev code. More complex fbdev drivers can be refactored step-by-step into a DRM -driver with the help of the DRM fbconv helpers. [1] These helpers provide +driver with the help of the DRM fbconv helpers [4]_. These helpers provide the transition layer between the DRM core infrastructure and the fbdev driver interface. Create a new DRM driver on top of the fbconv helpers, copy over the fbdev driver, and hook it up to the DRM code. Examples for -several fbdev drivers are available at [1] and a tutorial of this process -available at [2]. The result is a primitive DRM driver that can run X11 -and Weston. +several fbdev drivers are available in Thomas Zimmermann's fbconv tree +[4]_, as well as a tutorial of this process [5]_. The result is a primitive +DRM driver that can run X11 and Weston. - - [1] https://gitlab.freedesktop.org/tzimmermann/linux/tree/fbconv - - [2] https://gitlab.freedesktop.org/tzimmermann/linux/blob/fbconv/drivers/gpu/drm/drm_fbconv_helper.c + .. [4] https://gitlab.freedesktop.org/tzimmermann/linux/tree/fbconv + .. [5] https://gitlab.freedesktop.org/tzimmermann/linux/blob/fbconv/drivers/gpu/drm/drm_fbconv_helper.c Contact: Thomas Zimmermann <tzimmermann@suse.de> |