From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752933AbeEOShX (ORCPT ); Tue, 15 May 2018 14:37:23 -0400 Received: from mga01.intel.com ([192.55.52.88]:43027 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751099AbeEOShW (ORCPT ); Tue, 15 May 2018 14:37:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,404,1520924400"; d="scan'208";a="42034960" Message-ID: Subject: Re: [PATCH v1 0/3] console, serial8250: Disable PM and DMA ops From: Andy Shevchenko To: Petr Mladek , Sergey Senozhatsky , Steven Rostedt , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org, Sebastian Andrzej Siewior , Arnd Bergmann Cc: Tony Lindgren Date: Tue, 15 May 2018 21:37:18 +0300 In-Reply-To: <20180515183409.78046-1-andriy.shevchenko@linux.intel.com> References: <20180515183409.78046-1-andriy.shevchenko@linux.intel.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.1-2 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 Tue, 2018-05-15 at 21:34 +0300, Andy Shevchenko wrote: > Kernel console is sensitive to any kind of complex work needed to > print > out anything on it. One such case is emergency print during Oops. > > This series proposes to disable runtime PM and DMA operations on 8250 > serial console. > > More detailed explanation why is provided in patch 2. > > The series has been in our internal trees for years already with no > problems observed. +Cc: Tony. You might have some thoughts / test means for this. > > Andy Shevchenko (3): > console: introduce ->exit() callback > serial: 8250_port: Don't use power management for kernel console > serial: 8250_port: Disable DMA operations for kernel console > > drivers/tty/serial/8250/8250_core.c | 9 +++++++++ > drivers/tty/serial/8250/8250_port.c | 27 ++++++++++++++++++++++----- > include/linux/console.h | 1 + > include/linux/serial_8250.h | 1 + > kernel/printk/printk.c | 3 +++ > 5 files changed, 36 insertions(+), 5 deletions(-) > -- Andy Shevchenko Intel Finland Oy