drm/Documentation: Refine TODO for backlight helpers in tinydrm
Add a summary which resulted from discussions on what should
be done to refactor backlight helpers in tinydrm so that
they can be used in other drivers as well.
Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170927105116.GA30391@meghana-HP-Pavilion-Notebook
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 5f48702..92ee2f9 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -351,7 +351,16 @@
- backlight helpers, probably best to put them into a new drm_backlight.c.
This is because drivers/video is de-facto unmaintained. We could also
move drivers/video/backlight to drivers/gpu/backlight and take it all
- over within drm-misc, but that's more work.
+ over within drm-misc, but that's more work. Backlight helpers require a fair
+ bit of reworking and refactoring. A simple example is the enabling of a backlight.
+ Tinydrm has helpers for this. It would be good if other drivers can also use the
+ helper. However, there are various cases we need to consider i.e different
+ drivers seem to have different ways of enabling/disabling a backlight.
+ We also need to consider the backlight drivers (like gpio_backlight). The situation
+ is further complicated by the fact that the backlight is tied to fbdev
+ via fb_notifier_callback() which has complicated logic. For further details, refer
+ to the following discussion thread:
+ https://groups.google.com/forum/#!topic/outreachy-kernel/8rBe30lwtdA
- spi helpers, probably best put into spi core/helper code. Thierry said
the spi maintainer is fast&reactive, so shouldn't be a big issue.