From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84136C6379F for ; Fri, 10 Feb 2023 10:54:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231531AbjBJKyU (ORCPT ); Fri, 10 Feb 2023 05:54:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231786AbjBJKyR (ORCPT ); Fri, 10 Feb 2023 05:54:17 -0500 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4928B212A1 for ; Fri, 10 Feb 2023 02:54:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676026456; x=1707562456; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version:content-transfer-encoding; bh=AqOM13J9VRPclf+hYsuTaxcBQktb1KPvyl1aqw26wok=; b=Siz8jNzpeYIJvAaGlB6IxdFeO+L1l9XtjsvfPjoHN34WMSke8fi15P1/ CdRzwdTnfE5u1EIc60IqYEN6nKykx5czNAvxJIxlYU0KwQxKP0Dh9fEKy icE9k3HGerXXiW8l8H1QhyN4my4Uo7D4sCCdPV7trXD58kLs3N5M2w6zU FOHza3Wdbg38lQ3vxL8KtPEjDNtGfjUz3xnNx4Dca53/LJ9OHnZNJTqN4 Ee1MMW/w7JTbKphY48sKVlyagvkQClFerNXJcOtuDd0vx3X8o0r7CgNqT T2yv0cPR5outUHyBUSZU7sxSqj1WIaX2HXmdiZtXC9kZ2jUGlD+HBiS19 g==; X-IronPort-AV: E=McAfee;i="6500,9779,10616"; a="394996940" X-IronPort-AV: E=Sophos;i="5.97,286,1669104000"; d="scan'208";a="394996940" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2023 02:54:15 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10616"; a="645594214" X-IronPort-AV: E=Sophos;i="5.97,286,1669104000"; d="scan'208";a="645594214" Received: from myegin-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.38.74]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2023 02:54:12 -0800 From: Jani Nikula To: Greg Kroah-Hartman Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Ville =?utf-8?B?U3lyasOkbMOk?= , Jim Cromie , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , stable@vger.kernel.org Subject: Re: [PATCH] drm: Disable dynamic debug as broken In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20230207143337.2126678-1-jani.nikula@intel.com> Date: Fri, 10 Feb 2023 12:54:09 +0200 Message-ID: <878rh5x032.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, 07 Feb 2023, Greg Kroah-Hartman wrote: > On Tue, Feb 07, 2023 at 04:33:37PM +0200, Jani Nikula wrote: >> From: Ville Syrj=C3=A4l=C3=A4 >>=20 >> 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. >>=20 >> 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. >>=20 >> [1] https://lore.kernel.org/r/20230125203743.564009-1-jim.cromie@gmail.c= om >>=20 >> Fixes: 84ec67288c10 ("drm_print: wrap drm_*_dbg in dyndbg descriptor fac= tory macro") >> Cc: Jim Cromie >> Cc: Greg Kroah-Hartman >> Cc: Maarten Lankhorst >> Cc: Maxime Ripard >> Cc: Thomas Zimmermann >> Cc: David Airlie >> Cc: Daniel Vetter >> Cc: dri-devel@lists.freedesktop.org >> Cc: # v6.1+ >> Signed-off-by: Ville Syrj=C3=A4l=C3=A4 >> Signed-off-by: Jani Nikula >> --- >> drivers/gpu/drm/Kconfig | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >>=20 >> 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 >>=20=20 >> 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 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. --=20 Jani Nikula, Intel Open Source Graphics Center