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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 567DEC468C6 for ; Thu, 19 Jul 2018 06:50:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06714206B7 for ; Thu, 19 Jul 2018 06:50:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 06714206B7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=atomide.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 S1730213AbeGSHcL (ORCPT ); Thu, 19 Jul 2018 03:32:11 -0400 Received: from muru.com ([72.249.23.125]:52088 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727399AbeGSHcK (ORCPT ); Thu, 19 Jul 2018 03:32:10 -0400 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 11E5C80BF; Thu, 19 Jul 2018 06:53:47 +0000 (UTC) Date: Wed, 18 Jul 2018 23:50:33 -0700 From: Tony Lindgren To: Andy Shevchenko Cc: Andy Shevchenko , Sebastian Andrzej Siewior , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Linux Kernel Mailing List , Greg Kroah-Hartman , Jiri Slaby , "open list:SERIAL DRIVERS" , Arnd Bergmann Subject: Re: [PATCH v1 0/3] console, serial8250: Disable PM and DMA ops Message-ID: <20180719065033.GK99251@atomide.com> References: <20180516100842.xuma7b3e727w7bpz@linutronix.de> <20180516104734.357oevogppu5bsg4@linutronix.de> <20180517134820.GI98604@atomide.com> <20180517194834.GW25808@atomide.com> <20180523180052.GP98604@atomide.com> <9bc02408588716c4ddb5a2ffb7d915019433fedc.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9bc02408588716c4ddb5a2ffb7d915019433fedc.camel@linux.intel.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andy Shevchenko [180718 14:54]: > On Wed, 2018-05-23 at 11:00 -0700, Tony Lindgren wrote: > > I thought you said earlier the issue was that you wanted to keep > > the console enabled all the time and never idle? > > Yes, for kernel console. > To be clear, if user supplies "console=ttySx" it keeps powered on > always. But if there is no such parameter, we are fine with RPM. I'm fine with that as long as we have a way to detach or disable kernel console from userspace after booting so the console uart can idle. > Letting kernel console do power management on the systems without > irq_safe hack is dangerous in terms of loosing important data (crash, or > some other stuff which needs atomic context: kgdb?). Yes in the long run we should get rid of all pm_runtime_irq_safe() use. It increases the parent dev PM runtime usage count permanently blocking the whole domain from idling. Regards, Tony