Subject: Re: [PATCH] phy: phylink: Fix CuSFP issue in phylink

From: Bjarni Jonasson <[email-masked]>
Date: Wed, 11 Nov 2020 09:52:18 +0100

Russell King - ARM Linux admin writes:

> On Tue, Nov 10, 2020 at 03:16:34PM +0100, Bjarni Jonasson wrote:
>>
>> Russell King - ARM Linux admin writes:
>>
>> > On Tue, Nov 10, 2020 at 11:06:42AM +0100, Bjarni Jonasson wrote:
>> >> There is an issue with the current phylink driver and CuSFPs which
>> >> results in a callback to the phylink validate function without any
>> >> advertisement capabilities.  The workaround (in this changeset)
>> >> is to assign capabilities if a 1000baseT SFP is identified.
>> >
>> > How does this happen?  Which PHY is being used?
>>
>> This occurs just by plugging in the CuSFP.
>> None of the CuSFPs we have tested are working.
>> This is a dump from 3 different CuSFPs, phy regs 0-3:
>> FS SFP: 01:40:79:49
>> HP SFP: 01:40:01:49
>> Marvel SFP: 01:40:01:49
>> This was working before the delayed mac config was implemented (in dec
>> 2019).
>
> You're dumping PHY registers 0 and 1 there, not 0 through 3, which
> the values confirm. I don't recognise the format either. PHY registers
> are always 16-bit.
Sorry about that. Here is it again:
Marvell SFP : 0x0140 0x0149 0x0141 0x0cc1
FS SFP      : 0x1140 0x7949 0x0141 0x0cc2
Cisco SFP   : 0x0140 0x0149 0x0141 0x0cc1
I.e. its seems to be a Marvell phy (0x0141) in all cases.
And this occurs when phylink_start() is called.
--
Bjarni Jonasson, Microchip