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

Giulio Benetti giulio.benetti at micronovasrl.com
Fri Feb 2 07:38:13 PST 2018


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"

> 
> Maxime
> 


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Giulio Benetti
R&D Manager &
Advanced Research

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