From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S937196AbeE3Hod (ORCPT <rfc822;w@1wt.eu>);
        Wed, 30 May 2018 03:44:33 -0400
Received: from smtp.codeaurora.org ([198.145.29.96]:34378 "EHLO
        smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1752842AbeE3Hob (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 30 May 2018 03:44:31 -0400
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII;
 format=flowed
Content-Transfer-Encoding: 7bit
Date: Wed, 30 May 2018 00:44:29 -0700
From: okaya@codeaurora.org
To: Christoph Hellwig <hch@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-pci@vger.kernel.org, timur@codeaurora.org,
        linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Jonathan Corbet <corbet@lwn.net>, Bjorn Helgaas <bhelgaas@google.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
        Christoffer Dall <cdall@linaro.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Marc Zyngier <marc.zyngier@arm.com>,
        Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Thymo van Beers <thymovanbeers@gmail.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        David Rientjes <rientjes@google.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Keith Busch <keith.busch@intel.com>,
        Dongdong Liu <liudongdong3@huawei.com>,
        Frederick Lawler <fred@fredlawl.com>,
        Oza Pawandeep <poza@codeaurora.org>,
        Gabriele Paoloni <gabriele.paoloni@huawei.com>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] PCI: Add pci=safemode option
In-Reply-To: <20180530073735.GA28793@infradead.org>
References: <1527650389-31575-1-git-send-email-okaya@codeaurora.org>
 <20180530043103.GA19734@kroah.com>
 <6c317ed8-cca3-8862-5f3b-12cf14e4d53b@codeaurora.org>
 <20180530073735.GA28793@infradead.org>
Message-ID: <6dfe2db8f974d94c9867f30ec83d9333@codeaurora.org>
User-Agent: Roundcube Webmail/1.2.5
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 2018-05-30 00:37, Christoph Hellwig wrote:
> On Tue, May 29, 2018 at 09:41:33PM -0700, Sinan Kaya wrote:
>> Bjorn and I discussed the need for such a "safe" mode feature when you
>> want to bring up PCI for a platform. You want to turn off everything 
>> as
>> a starter and just stick to bare minimum.
> 
> Can we please make it a config option the instead of adding code
> to every kernel?  Also maybe the bringup should be in the name
> to make this more clear?

One other requirement was to have a runtime option rather than compile 
time option.

When someone reported a problem, we wanted to be able to say "use this 
option and see if system boots" without doing any bisects or 
recompilation.

This would be the first step in troubleshooting a system to see if 
fundamental features are working.

I don't mind changing the name
Bjorn mentioned safe option. I made it safemode. I am looking at Bjorn 
for suggestions at this moment.