Message-ID: <53021BD2.3090301@free-electrons.com>
Date: Mon, 17 Feb 2014 15:25:22 +0100
From: Gregory CLEMENT <gregory.clement@free-electrons.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0
MIME-Version: 1.0
To: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
        Jason Cooper <jason@lakedaemon.net>,
        =?UTF-8?B?RW1pbGlvIEzDs3Bleg==?= <emilio@elopez.com.ar>,
        Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
        Andrew Lunn <andrew@lunn.ch>, Mike Turquette <mturquette@linaro.org>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 0/4] clk: mvebu: fix clk init order
References: <1390673950-4521-1-git-send-email-sebastian.hesselbarth@gmail.com> <20140205183457.GW8533@titan.lakedaemon.net> <20140217141336.GA2765@localhost>
In-Reply-To: <20140217141336.GA2765@localhost>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

On 17/02/2014 15:13, Ezequiel Garcia wrote:
> On Wed, Feb 05, 2014 at 01:34:57PM -0500, Jason Cooper wrote:
>> On Sat, Jan 25, 2014 at 07:19:06PM +0100, Sebastian Hesselbarth wrote:
>>> This patch set fixes clk init order that went upside-down with
>>> v3.14. I haven't really investigated what caused this, but I assume
>>> it is related with DT node reordering by addresses.
>>>
>>> Anyway, with v3.14 for MVEBU SoCs, the clock gating driver gets
>>> registered before core clocks driver. Unfortunately, we cannot
>>> return -EPROBE_DEFER in drivers initialized by clk_of_init. As the
>>> init order for our drivers is always core clocks before clock gating,
>>> we maintain init order ourselves by hooking CLK_OF_DECLARE to one
>>> init function that will register core clocks before clock gating
>>> driver.
>>>
>>> This patch is based on pre-v3.14-rc1 mainline and should go in as
>>> fixes for it. As we now send MVEBU clk pull-requests to Mike directly,
>>> I suggest Jason picks it up as a topic branch.
>>>
>>> The patches have been boot tested on Dove and compile-tested only
>>> for Kirkwood, Armada 370 and XP.
>>>
>>> Sebastian Hesselbarth (4):
>>>   clk: mvebu: armada-370: maintain clock init order
>>>   clk: mvebu: armada-xp: maintain clock init order
>>>   clk: mvebu: dove: maintain clock init order
>>>   clk: mvebu: kirkwood: maintain clock init order
>>>
>>>  drivers/clk/mvebu/armada-370.c | 21 ++++++++++-----------
>>>  drivers/clk/mvebu/armada-xp.c  | 20 +++++++++-----------
>>>  drivers/clk/mvebu/dove.c       | 19 +++++++++----------
>>>  drivers/clk/mvebu/kirkwood.c   | 34 ++++++++++++++++------------------
>>>  4 files changed, 44 insertions(+), 50 deletions(-)
>>
>> Whole series applied to mvebu/clk-fixes.
>>
> 
> Are we still in time to consider Emilio's oneline proposal?
> (Emilio: would you mind preparing a suitable patch against dove,
> kirkwood, armada370/xp, so we can see the real thing?).

I am still strongly against this proposal because hard-coded the parent
clock name in the driver seems very wrong and moreover in some circumstances
(if there is no output-name, which is our default case) this proposal
just ignored the parent clock given by the device tree and this looked
more wrong.

> 
> Sebastian fix works perfect, and it easy to understand. However, it has
> quite a large diffstat. When compared to Emilio's oneline proposal, it
> seems to me it would be preferable, unless it's broken.
> 
> Workaround or not, the fact is this code will be in v3.14, so maybe we
> can spend some time considering a cleaner option.
> 
> Or is this just rubbish?
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/