From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753321AbdFMMya (ORCPT ); Tue, 13 Jun 2017 08:54:30 -0400 Received: from mx2.suse.de ([195.135.220.15]:53571 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753103AbdFMMy3 (ORCPT ); Tue, 13 Jun 2017 08:54:29 -0400 From: Petr Mladek To: Sergey Senozhatsky , Steven Rostedt Cc: Andrew Morton , Peter Zijlstra , Aleksey Makarov , Sabrina Dubroca , Sudeep Holla , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Petr Mladek Subject: [PATCH 0/3] printk/console: Simplify the logic and always have a preferred console Date: Tue, 13 Jun 2017 14:54:01 +0200 Message-Id: <1497358444-30736-1-git-send-email-pmladek@suse.com> X-Mailer: git-send-email 1.8.5.6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The regression caused by the commit cf39bf58afdaabc0b ("printk: fix double printing with earlycon") made me to investigate the console registration code from many angles. And it was not an easy reading. Especially the logic around the preferred console was somehow twisted. The first two patches try to make it more straightforward. The good thing is that they should not change the behavior. Another problem was inconsistency in handling a fallback for the preferred console. This is solved by the 3rd patch. Also it solves a bug report related to "showconsole" that I got 2 weeks ago. This fix slightly changes the order of non-preferred consoles. But I believe that it is behind the border when we need to take care of backward compatibility. Sadly, we had to revert the fix of the duplicated output. It is not solved by this patch set. I consider this a cosmetic issue. A proper solution would be quite complicated. It might involve rework of the console->match() functions and allow to match aliases without side effects. Alternative solution would be an additional command line option that would force handling of CON_PRINTBUFFER flag and "never", "auto", or "always" reply the buffer for newly registered consoles. But I am not sure if it is worth it. Petr Mladek (3): printk/console: Remove superfluous setting of has_preferred state value printk/console: Clean up logic around fallback console printk/console: Always have a preferred console kernel/printk/printk.c | 48 ++++++++++++++++++++---------------------------- 1 file changed, 20 insertions(+), 28 deletions(-) -- 1.8.5.6