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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 B7F2BECDFBB for ; Wed, 18 Jul 2018 14:51:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C38B2075C for ; Wed, 18 Jul 2018 14:51:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C38B2075C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.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 S1731166AbeGRP3Q (ORCPT ); Wed, 18 Jul 2018 11:29:16 -0400 Received: from mga14.intel.com ([192.55.52.115]:63821 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730987AbeGRP3P (ORCPT ); Wed, 18 Jul 2018 11:29:15 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Jul 2018 07:50:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,370,1526367600"; d="scan'208";a="58662792" Received: from smile.fi.intel.com (HELO smile) ([10.237.72.86]) by orsmga006.jf.intel.com with ESMTP; 18 Jul 2018 07:50:56 -0700 Message-ID: <9bc02408588716c4ddb5a2ffb7d915019433fedc.camel@linux.intel.com> Subject: Re: [PATCH v1 0/3] console, serial8250: Disable PM and DMA ops From: Andy Shevchenko To: Tony Lindgren , Andy Shevchenko Cc: Sebastian Andrzej Siewior , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Linux Kernel Mailing List , Greg Kroah-Hartman , Jiri Slaby , "open list:SERIAL DRIVERS" , Arnd Bergmann Date: Wed, 18 Jul 2018 17:50:55 +0300 In-Reply-To: <20180523180052.GP98604@atomide.com> References: <20180515183409.78046-1-andriy.shevchenko@linux.intel.com> <20180516100842.xuma7b3e727w7bpz@linutronix.de> <20180516104734.357oevogppu5bsg4@linutronix.de> <20180517134820.GI98604@atomide.com> <20180517194834.GW25808@atomide.com> <20180523180052.GP98604@atomide.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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2018-05-23 at 11:00 -0700, Tony Lindgren wrote: > * Andy Shevchenko [180522 21:54]: > > On Thu, May 17, 2018 at 10:48 PM, Tony Lindgren > > wrote: > > > * Andy Shevchenko [180517 16:38]: > > > > On Thu, May 17, 2018 at 4:48 PM, Tony Lindgren > > > > wrote: > > > > > * Sebastian Andrzej Siewior [180516 > > > > > 10:49]: > > > > > The idea breaking PM seems silly to me considering that we've > > > > > had > > > > > it working for years already. > > > > > > > > Same question / note. World is much more complex than just > > > > being OMAP. > > > > > > Sorry but you are making assumptions about hardware being powered > > > on > > > all the time. > > > > Nope, other way around. The so called "support" _prevents_ our > > hardware to go to sleep. > > Hmm sorry now I'm all confused what issues you're having. > > 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. 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?). -- Andy Shevchenko Intel Finland Oy