From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932536AbaEPNtL (ORCPT ); Fri, 16 May 2014 09:49:11 -0400 Received: from helium.waldemar-brodkorb.de ([89.238.66.15]:49333 "EHLO helium.waldemar-brodkorb.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756368AbaEPNtI (ORCPT ); Fri, 16 May 2014 09:49:08 -0400 Date: Fri, 16 May 2014 15:49:04 +0200 From: Waldemar Brodkorb To: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org, Geert Uytterhoeven , Greg Kroah-Hartman Subject: serial console on rb532 disabled on boot (linux 3.15rc5) Message-ID: <20140516134904.GW618@waldemar-brodkorb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Operating-System: Linux 3.2.0-4-amd64 x86_64 User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Linux hackers, I am trying to bootup my Mikrotik RB532 board with the latest kernel, but my serial console is disabled after boot: .. Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled serial8250: ttyS0 at MMIO 0x0 (irq = 104, base_baud = 12499875) is a 16550A console [ttyS0] enabled console [ttyS0] disabled I used git bisect to find the problematic commit: commit 5f5c9ae56c38942623f69c3e6dc6ec78e4da2076 Author: Geert Uytterhoeven Date: Fri Feb 28 14:21:32 2014 +0100 serial_core: Unregister console in uart_remove_one_port() If the serial port being removed is used as a console, it must also be unregistered from the console subsystem using unregister_console(). uart_ops.release_port() will release resources (e.g. iounmap() the serial port registers), causing a crash on subsequent kernel output if the console is still registered. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman After reverting the change, everything is fine. I can provide a .config and dmesg if needed. Thanks in advance Waldemar