From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933311AbcLMOmt (ORCPT ); Tue, 13 Dec 2016 09:42:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:54586 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932358AbcLMOms (ORCPT ); Tue, 13 Dec 2016 09:42:48 -0500 Message-ID: <1481640165.4190.11.camel@chaos.suse> Subject: Re: [PATCH] firmware: dmi_scan: Always show system identification string From: Jean Delvare To: Ard Biesheuvel Cc: Kefeng Wang , Mark Rutland , "linux-kernel@vger.kernel.org" Date: Tue, 13 Dec 2016 15:42:45 +0100 In-Reply-To: References: <1481266447-51471-1-git-send-email-wangkefeng.wang@huawei.com> <5d02bf23-fe10-53d3-f6b8-d7dc0400637e@huawei.com> Organization: Suse Linux Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On mar., 2016-12-13 at 14:25 +0000, Ard Biesheuvel wrote: > On 12 December 2016 at 01:51, Kefeng Wang wrote: > > > > > > On 2016/12/9 22:55, Ard Biesheuvel wrote: > >> On 9 December 2016 at 06:54, Kefeng Wang wrote: > >>> Let's keep consistent when print dmi_ids_string between SMBIOS 2.x > >>> and SMBIOS 3.x, and always show the system identification string, > >>> like Vendor, Product/Board name and BIOS infos. > >>> > >> > >> Are you saying the printk(KERN_DEBUG) was inconsistent with the > >> pr_debug() before? > > > > Yes, found it when check the boot dmesg on qemu, there is no print using pr_debug > > with defconfig on ARM64( smbios3 present), but could shown with printk(KERN_DEBUG. > > > > That's interesting. I would assume pr_debug and printk(KERN_DEBUG) to > behave identically ... And you'd be wrong ;-) >>From include/linux/printk.h: 304 #if defined(CONFIG_DYNAMIC_DEBUG) 305 #include 306 307 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */ 308 #define pr_debug(fmt, ...) \ 309 dynamic_pr_debug(fmt, ##__VA_ARGS__) 310 #elif defined(DEBUG) 311 #define pr_debug(fmt, ...) \ 312 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) 313 #else 314 #define pr_debug(fmt, ...) \ 315 no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) 316 #endif Which basically means that pr_debug() has no effect unless debugging is actually enabled, while printk(KERN_DEBUG ...) is always printed by the kernel (with a log level which may or may not make it to a specific output.) -- Jean Delvare SUSE L3 Support