[PATCH] clk: sunxi-ng: ccu-sun4i-a10: Fix mali changing dclk frequency

Giulio Benetti giulio.benetti at micronovasrl.com
Fri Feb 2 09:21:18 PST 2018


Hi,

Il 02/02/2018 16:52, Maxime Ripard ha scritto:
> On Fri, Feb 02, 2018 at 04:38:13PM +0100, Giulio Benetti wrote:
>> Hi,
>>
>> Il 02/02/2018 14:35, Maxime Ripard ha scritto:
>>> On Fri, Feb 02, 2018 at 11:57:20AM +0100, Giulio Benetti wrote:
>>>> Il 02/02/2018 11:53, Maxime Ripard ha scritto:
>>>>> Hi,
>>>>>
>>>>> On Thu, Feb 01, 2018 at 05:17:11PM +0100, Giulio Benetti wrote:
>>>>>>>>> What kernel version did you use?
>>>>>>>>
>>>>>>>> Latest mainline.
>>>>>>>
>>>>>>> I guess this patch could fix it:
>>>>>>> http://code.bulix.org/1kitrq-268936?raw
>>>>>>
>>>>>> This should prevent from modifying parent clock. But my problem was
>>>>>> different.
>>>>>>
>>>>>> On A20, gpu_clk can have different PLL, not I've found out the way
>>>>>> to choose right one with assigned-parent-clocks.
>>>>>>
>>>>>> I have patchset ready for adding A20 mali node, but I need some more
>>>>>> time to complete with OPP, then I will submit entire patchset.
>>>>>>
>>>>>> Now it works correctly, using right pll(dedicated PLL8), setting
>>>>>> right frequency.
>>>>>
>>>>> The point is that we really don't care about which PLL is actually
>>>>> being used, as long as the rate is correct and we don't break anything
>>>>> else. If the GPU rate is accessible through one of the other PLL, it
>>>>> makes even more sense to not use the GPU PLL and keep it disabled,
>>>>> since it will result in some power savings.
>>>>
>>>> Ah! I see the point now, very clever system for power saving.
>>>> I'm going to check if it's resolutive,
>>>> but it sounds good.
>>>>
>>>>>
>>>>>> Btw, do I need to add a board using it, or can I add only Mali node
>>>>>> to sun7i-a20.dtsi(plus other little patches)?
>>>>>
>>>>> You can add it to the DTSI without a board using it (and actually,
>>>>> nothing should be in the board DTS, everything in the DT for the Mali
>>>>> applies to all boards).
>>>>
>>>> Sure. So I would also add the patch you've addressed me:
>>>> http://code.bulix.org/1kitrq-268936?raw
>>>> as a commit. Can I submit it in patchset to complete the whole job?
>>>
>>> I already sent that patch quite some time ago, I'll just apply it. You
>>> can send the DT patch :)
>>
>> Thanks. Sorry for my ignorance, but where are you applying patches?
>> Because I've tried to check sunxi-next and a lot of other Repo but I can't
>> find this and neither "Re: [PATCH] clk: sunxi-ng: ccu-sun4i-a10: Fix mali
>> changing dclk frequency"
> 
> Usually, in the git tree listed in MAINTAINERS :)

Please don't laugh at me! :)

I've tried to check for your patch(drivers/gpu/drm/sun4i/sun4i_tcon.c) on:
https://cgit.freedesktop.org/drm/drm-misc/
according to MAINTAINERS file and nothing found.

For the other one(arch/arm/boot/dts/sun7i-a20.dtsi), I've checked
on:
https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/
https://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasing.git/

Nothing neither here!

In MAINTANERS file there's no arch/arm/boot/dts/sun* association.

I don't know where else to look, I'm going nut!
And for sure I'm looking idiot,
this is why I've prepended "Please don't laugh at me!" :))

Help!

> 
> Maxime
> 


-- 
Giulio Benetti
R&D Manager &
Advanced Research

MICRONOVA SRL
Sede: Via A. Niedda 3 - 35010 Vigonza (PD)
Tel. 049/8931563 - Fax 049/8931346
Cod.Fiscale - P.IVA 02663420285
Capitale Sociale € 26.000 i.v.
Iscritta al Reg. Imprese di Padova N. 02663420285
Numero R.E.A. 258642



More information about the linux-arm-kernel mailing list