On Fri, 10 Feb 2023, Jani Nikula <jani.nikula@xxxxxxxxx> wrote: > On Tue, 07 Feb 2023, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> 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> > > Thanks Greg, any more acks from anyone? > > Maxime, since there's going to be an -rc8, I suggest taking this via > drm-misc-fixes. Is that okay with you? (You're doing drm-misc-fixes this > round, right?) Pushed to drm-misc-fixes with Maxime's IRC ack and Jim's ack elsewhere in the thread. Thanks. BR, Jani. > > BR, > Jani. -- Jani Nikula, Intel Open Source Graphics Center
