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

[Frank Wunderlich]

Am 10. Juni 2025 14:58:44 MESZ schrieb Andrew Lunn <andrew at 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 comment out of date?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 at 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