This is a note to let you know that I've just added the patch titled
drm: Disable dynamic debug as broken
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-disable-dynamic-debug-as-broken.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bb2ff6c27bc9e1da4d3ec5e7b1d6b9df1092cb5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Tue, 7 Feb 2023 16:33:37 +0200
Subject: drm: Disable dynamic debug as broken
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From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
commit bb2ff6c27bc9e1da4d3ec5e7b1d6b9df1092cb5a upstream.
CONFIG_DRM_USE_DYNAMIC_DEBUG breaks debug prints for (at least modular)
drm drivers. The debug prints can be reinstated by manually frobbing
/sys/module/drm/parameters/debug after the fact, but at that point the
damage is done and all debugs from driver probe are lost. This makes
drivers totally undebuggable.
There's a more complete fix in progress [1], with further details, but
we need this fixed in stable kernels. Mark the feature as broken and
disable it by default, with hopes distros follow suit and disable it as
well.
[1] https://lore.kernel.org/r/20230125203743.564009-1-jim.cromie@xxxxxxxxx
Fixes: 84ec67288c10 ("drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro")
Cc: Jim Cromie <jim.cromie@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # v6.1+
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Acked-by: Jim Cromie <jim.cromie@xxxxxxxxx>
Acked-by: Maxime Ripard <maxime@xxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230207143337.2126678-1-jani.nikula@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/Kconfig | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 315cbdf61979..9abfb482b615 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -53,7 +53,8 @@ config DRM_DEBUG_MM
config DRM_USE_DYNAMIC_DEBUG
bool "use dynamic debug to implement drm.debug"
- default y
+ default n
+ depends on BROKEN
depends on DRM
depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
depends on JUMP_LABEL
--
2.39.1
Patches currently in stable-queue which might be from ville.syrjala@xxxxxxxxxxxxxxx are
queue-6.1/drm-disable-dynamic-debug-as-broken.patch
