Re: Re: [PATCH v3 12/13] arm64: dts: mediatek: mt7988a-bpi-r4: add sfp cages and link to gmac

Frank Wunderlich
2025-06-11T22:40:15Z

Am 10. Juni 2025 14:58:44 MESZ schrieb Andrew Lunn <andrew@lunn.ch>:
>> > sff,sfp.yaml says:
>> >
>> > maximum-power-milliwatt:
>> > minimum: 1000
>> > default: 1000
>> > description:
>> > Maximum module power consumption Specifies the maximum power consumption
>> > allowable by a module in the slot, in milli-Watts. Presently, modules can
>> > be up to 1W, 1.5W or 2W.
>> >
>> > I've no idea what will happen when the SFP core sees 3000. Is the
>> > comment out of date?
>>
>> at least sfp-core has no issue with the setting
>>
>> root@bpi-r4-phy-8G:~# dmesg | grep sfp
>> [ 1.269437] sfp sfp1: Host maximum power 3.0W
>> [ 1.613749] sfp sfp1: module CISCO-FINISAR FTLX8571D3BCL-C2 rev A sn S2209167650 dc 220916
>>
>> imho some modules require more than 2W (some gpon/xpon and 10G copper ethernet).
>
>Looking at the code:
>
>static int sfp_module_parse_power(struct sfp *sfp)
>{
> u32 power_mW = 1000;
> bool supports_a2;
>
> if (sfp->id.ext.sff8472_compliance >= SFP_SFF8472_COMPLIANCE_REV10_2 &&
> sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_POWER_DECL))
> power_mW = 1500;
> /* Added in Rev 11.9, but there is no compliance code for this */
> if (sfp->id.ext.sff8472_compliance >= SFP_SFF8472_COMPLIANCE_REV11_4 &&
> sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_HIGH_POWER_LEVEL))
> power_mW = 2000;
>
>How does your module indicate it needs 3000 mW? Does this bit of code
>need extending to read additional bits?

Message says "host maximum power",not that sfp needs the 3w.

> Andrew

regards Frank