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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80508C04EB9 for ; Thu, 6 Dec 2018 02:51:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36DD8214C1 for ; Thu, 6 Dec 2018 02:51:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36DD8214C1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728770AbeLFCvr (ORCPT ); Wed, 5 Dec 2018 21:51:47 -0500 Received: from smtprelay0143.hostedemail.com ([216.40.44.143]:56688 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727804AbeLFCvr (ORCPT ); Wed, 5 Dec 2018 21:51:47 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay08.hostedemail.com (Postfix) with ESMTP id B77A7182CED34; Thu, 6 Dec 2018 02:51:45 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: ray11_666d8984bb302 X-Filterd-Recvd-Size: 3538 Received: from XPS-9350.home (unknown [47.151.153.53]) (Authenticated sender: joe@perches.com) by omf11.hostedemail.com (Postfix) with ESMTPA; Thu, 6 Dec 2018 02:51:43 +0000 (UTC) Message-ID: <1586a49594d30b4bf4d88eba0d258e21efd26da2.camel@perches.com> Subject: Re: [PATCH 1/2] drm: Only #define DEBUG if CONFIG_DYNAMIC_DEBUG is disabled From: Joe Perches To: "Zhang, Jerry(Junwei)" , Michel =?ISO-8859-1?Q?D=E4nzer?= , Christian Koenig , Huang Rui , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Chris Wilson Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Date: Wed, 05 Dec 2018 18:51:42 -0800 In-Reply-To: <10fca21a-5d7c-fe9e-07f0-6200e9de538e@amd.com> References: <20181205165621.5805-1-michel@daenzer.net> <10fca21a-5d7c-fe9e-07f0-6200e9de538e@amd.com> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.30.1-1build1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2018-12-06 at 10:40 +0800, Zhang, Jerry(Junwei) wrote: > On 12/6/18 12:56 AM, Michel Dänzer wrote: > > From: Michel Dänzer > > > > The following cases are possible for pr_debug(): > > > > 1. CONFIG_DYNAMIC_DEBUG disabled > > a) DEBUG not defined: pr_debug() translates to no_printk(...), i.e. > > it never generates any output. > > b) DEBUG defined: pr_debug() translates to printk(KERN_DEBUG ...), > > i.e. it generates output which doesn't appear in dmesg by default, > > can be enabled dynamically. > > > > 2. CONFIG_DYNAMIC_DEBUG enabled: pr_debug() translates to > > dynamic_pr_debug() > > a) DEBUG not defined: dynamic_pr_debug() generates no output by > > default, can be enabled dynamically. > > b) DEBUG defined: dynamic_pr_debug() generates output by default, > > can be disabled dynamically. > > > > The intention for drm_debug_printer() is to generate output which > > doesn't appear in dmesg by default, but can be enabled dynamically, i.e. > > cases 1b) and 2a). However, defining DEBUG unconditionally gave us 2b) > > instead of 2a) with CONFIG_DYNAMIC_DEBUG enabled. > > > > Fixes: 79a5ad2fdb3c ("drm: Enable pr_debug() for drm_printer") I very much doubt this is a fix. Did you read the commit log for this commit? It says "make sure it will always produce output" And why didn't you cc Chris Wilson, the author of that patch? > > Signed-off-by: Michel Dänzer > Reviewed-by: Junwei Zhang > > > --- > > drivers/gpu/drm/drm_print.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > > index 0e7fc3e7dfb4..ee56e4a1b343 100644 > > --- a/drivers/gpu/drm/drm_print.c > > +++ b/drivers/gpu/drm/drm_print.c > > @@ -23,11 +23,13 @@ > > * Rob Clark > > */ > > > > -#define DEBUG /* for pr_debug() */ > > - > > #include > > #include > > #include > > + > > +#ifndef CONFIG_DYNAMIC_DEBUG > > +#define DEBUG /* for pr_debug() */ > > +#endif > > #include > > > > void __drm_puts_coredump(struct drm_printer *p, const char *str)