Merge tag 'drm-misc-next-2024-06-13' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next

drm-misc-next for 6.11:

UAPI Changes:

Cross-subsystem Changes:

Core Changes:
 - Sprinkle MODULE_DESCRIPTIONS everywhere they are missing
 - bridge: Remove drm_bridge_chain_mode_fixup
 - ci: Require a more recent version of mesa, improve farm estup and
   test generation
 - mipi-dbi: Remove mipi_dbi_machine_little_endian, make SPI bits per
   word configurable, support RGB888, and allow pixel formats to be
   specified in the DT.
 - mm: Remove drm_mm_replace_node
 - panic: Allow to dump kmsg to the screen
 - print: Add a drm prefix to warn level messages too, remove
   ___drm_dbg, consolidate prefix handling

Driver Changes:
 - sun4i: Rework the blender setup for DE2
 - bridges:
   - bridge-connector: Plumb in the new HDMI helpers
   - samsung-dsim: Fix timings calculation
   - tc358767: Plenty of small fixes
 - panels:
   - More cleanup of prepare / enable state tracking in drivers
   - New panel: PrimeView PM070WL4,

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <mripard@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240613-cicada-of-infinite-unity-0955ca@houat

1 files changed, 26 insertions, 21 deletions

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 2734b8a34541..2ea6ffc9b22b 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -469,30 +469,35 @@ 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.
+Remove disable/unprepare in remove/shutdown in panel-simple and panel-edp
+-------------------------------------------------------------------------
+
+As of commit d2aacaf07395 ("drm/panel: Check for already prepared/enabled in
+drm_panel"), we have a check in the drm_panel core to make sure nobody
+double-calls prepare/enable/disable/unprepare. Eventually that should probably
+be turned into a WARN_ON() or somehow made louder, but right now we actually
+expect it to trigger and so we don't want it to be too loud.
+
+Specifically, that warning will trigger for panel-edp and panel-simple at
+shutdown time because those panels hardcode a call to drm_panel_disable()
+and drm_panel_unprepare() at shutdown and remove time that they call regardless
+of panel state. On systems with a properly coded DRM modeset driver that
+calls drm_atomic_helper_shutdown() this is pretty much guaranteed to cause
+the warning to fire.
+
+Unfortunately we can't safely remove the calls in panel-edp and panel-simple
+until we're sure that all DRM modeset drivers that are used with those panels
+properly call drm_atomic_helper_shutdown(). This TODO item is to validate
+that all DRM modeset drivers used with panel-edp and panel-simple properly
+call drm_atomic_helper_shutdown() and then remove the calls to
+disable/unprepare from those panels. Alternatively, this TODO item could be
+removed by convincing stakeholders that those calls are fine and downgrading
+the error message in drm_panel_disable() / drm_panel_unprepare() to a
+debug-level message.
 
 Contact: Douglas Anderson <dianders@chromium.org>
 
-Level: Starter/Intermediate
+Level: Intermediate
 
 Transition away from using mipi_dsi_*_write_seq()
 -------------------------------------------------