Re: [PATCH v5 4/4] ARM: dts: qcom: ipq8064: Add CPU OPP table

Konrad Dybcio
2023-10-10T19:52:59Z

On 10/10/23 16:15, Christian Marangi wrote:
> On Tue, Oct 10, 2023 at 03:40:32PM +0200, Konrad Dybcio wrote:
>>
>>
>> On 9/30/23 12:21, Robert Marko wrote:
>>> From: Christian Marangi <ansuelsmth@gmail.com>
>>>
>>> Add CPU OPP table for IPQ8062, IPQ8064 and IPQ8065 SoC.
>>> Use opp-supported-hw binding to correctly enable and disable the
>>> frequency as IPQ8062 supports up to 1.0Ghz, IPQ8064 supports up to
>>> 1.4GHz with 1.2GHz as an additional frequency and IPQ8065 supports
>>> 1.7GHZ but doesn't have 1.2GHZ frequency and has to be disabled.
>>>
>>> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
>>> Signed-off-by: Robert Marko <robimarko@gmail.com>
>>> ---
>> Christian/Robert, can you provide a downstream source for this?
>>
>
> Sure, consider that everything is with +/-5%.
Hm, so you're e.g. putting ipq8062 384MHz voltage for PVS3 equal to
0.95*800000 = 760000, but I'm not sure if it's a good idea?

The comment in downstream:

"These are based on +/-5% Margin on the VDD_APCx that is advertised in
our Datasheet across Temperature"

suggests this is already not very accurate, and betting that the lower
threshold works on all chips is probably not the best idea.

Konrad