On Tue, Feb 07, 2023 at 04:33:37PM +0200, Jani Nikula wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > 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> > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> > --- > 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 f42d4c6a19f2..dc0f94f02a82 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -52,7 +52,8 @@ 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 Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
