Re: [PATCH 0/4] clk: mvebu: fix clk init order

[Gregory CLEMENT]

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
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