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 S1754747AbcHSTcA (ORCPT <rfc822;w@1wt.eu>);
        Fri, 19 Aug 2016 15:32:00 -0400
Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:43295
        "EHLO s-opensource.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1750906AbcHSTb6 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Fri, 19 Aug 2016 15:31:58 -0400
Subject: Re: [RFC 00/17] clk: Add per-controller locks to fix deadlocks
To: Krzysztof Kozlowski <k.kozlowski@samsung.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@codeaurora.org>,
        Stephen Warren <swarren@wwwdotorg.org>, Lee Jones <lee@kernel.org>,
        Eric Anholt <eric@anholt.net>, Florian Fainelli <f.fainelli@gmail.com>,
        Ray Jui <rjui@broadcom.com>, Scott Branden <sbranden@broadcom.com>,
        bcm-kernel-feedback-list@broadcom.com,
        Sylwester Nawrocki <s.nawrocki@samsung.com>,
        Tomasz Figa <tomasz.figa@gmail.com>, Kukjin Kim <kgene@kernel.org>,
        Russell King <linux@armlinux.org.uk>, Mark Brown <broonie@kernel.org>,
        linux-clk@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-samsung-soc@vger.kernel.org, linux-i2c@vger.kernel.org,
        alsa-devel@alsa-project.org
References: <1471354514-24224-1-git-send-email-k.kozlowski@samsung.com>
From: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
        Charles Keepax <ckeepax@opensource.wolfsonmicro.com>,
        a.hajda@samsung.com,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Message-ID: <8519a1cf-ec51-2914-e4aa-27b26b9233de@osg.samsung.com>
Date: Fri, 19 Aug 2016 15:31:08 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.0
MIME-Version: 1.0
In-Reply-To: <1471354514-24224-1-git-send-email-k.kozlowski@samsung.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hello Krzysztof,

On 08/16/2016 09:34 AM, Krzysztof Kozlowski wrote:
> Hi,
> 
> RFC, please, do not apply, maybe except patch #1 which is harmless.
> 
> 
> Introduction
> ============
> The patchset brings new entity: clock controller representing a hardware
> block.  The clock controller comes with its own prepare lock which
> is used then in many places.  The idea is to fix the deadlock mentioned
> in commit 10ff4c5239a1 ("i2c: exynos5: Fix possible ABBA deadlock by keeping
> I2C clock prepared") and commit 34e81ad5f0b6 ("i2c: s3c2410: fix ABBA deadlock
> by keeping clock prepared").
> 
> 

I'm not familiar enough with the common clock framework to do a proper review
of this patch-set, but I've tested both on an Exynos5800 Peach Pi Chromebook
and an Exynos5422 Odroid XU4 board and I didn't find any clock regressions.

Also, I confirmed that the possible deadlock in the Odroid XU4 that was fixed
by reverted commit 10ff4c5239a1 doesn't happen anymore with your patches.

Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America