On Tue, 07 Feb 2023, Greg Kroah-Hartman <gre...@linuxfoundation.org> wrote: > On Tue, Feb 07, 2023 at 04:33:37PM +0200, Jani Nikula wrote: >> From: Ville Syrjälä <ville.syrj...@linux.intel.com> >> >> 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.cro...@gmail.com >> >> Fixes: 84ec67288c10 ("drm_print: wrap drm_*_dbg in dyndbg descriptor factory >> macro") >> Cc: Jim Cromie <jim.cro...@gmail.com> >> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> >> Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com> >> Cc: Maxime Ripard <mrip...@kernel.org> >> Cc: Thomas Zimmermann <tzimmerm...@suse.de> >> Cc: David Airlie <airl...@gmail.com> >> Cc: Daniel Vetter <dan...@ffwll.ch> >> Cc: dri-de...@lists.freedesktop.org >> Cc: <sta...@vger.kernel.org> # v6.1+ >> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com> >> Signed-off-by: Jani Nikula <jani.nik...@intel.com> >> --- >> 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 <gre...@linuxfoundation.org>
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?) BR, Jani. -- Jani Nikula, Intel Open Source Graphics Center
