Commit bb2ff6c2 authored by Ville Syrjälä's avatar Ville Syrjälä Committed by Jani Nikula
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drm: Disable dynamic debug as broken

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@gmail.com



Fixes: 84ec6728 ("drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro")
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.1+
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: default avatarJim Cromie <jim.cromie@gmail.com>
Acked-by: default avatarMaxime Ripard <maxime@cerno.tech>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230207143337.2126678-1-jani.nikula@intel.com
parent 7484a5bc
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+2 −1
Original line number Diff line number Diff line
@@ -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