Re: [PATCH net-next v4 2/2] net: phy: broadcom: add 1000Base-X support for BCM54616S

[Tao Ren <taoren@fb.com>]

Hi Heiner,

On 8/7/19 9:24 PM, Tao Ren wrote:
> Hi Heiner,
> 
> On 8/7/19 12:18 PM, Heiner Kallweit wrote:
>> On 06.08.2019 23:42, Tao Ren wrote:
>>> Hi Andrew / Heiner / Vladimir,
>>>
>>> On 8/6/19 2:09 PM, Tao Ren wrote:
>>>> The BCM54616S PHY cannot work properly in RGMII->1000Base-KX mode (for
>>>> example, on Facebook CMM BMC platform), mainly because genphy functions
>>>> are designed for copper links, and 1000Base-X (clause 37) auto negotiation
>>>> needs to be handled differently.
>>>>
>>>> This patch enables 1000Base-X support for BCM54616S by customizing 3
>>>> driver callbacks:
>>>>
>>>>   - probe: probe callback detects PHY's operation mode based on
>>>>     INTERF_SEL[1:0] pins and 1000X/100FX selection bit in SerDES 100-FX
>>>>     Control register.
>>>>
>>>>   - config_aneg: bcm54616s_config_aneg_1000bx function is added for auto
>>>>     negotiation in 1000Base-X mode.
>>>>
>>>>   - read_status: BCM54616S and BCM5482 PHY share the same read_status
>>>>     callback which manually set link speed and duplex mode in 1000Base-X
>>>>     mode.
>>>>
>>>> Signed-off-by: Tao Ren <taoren@fb.com>
>>>
>>> I customized config_aneg function for BCM54616S 1000Base-X mode and link-down issue is also fixed: the patch is tested on Facebook CMM and Minipack BMC and everything looks normal. Please kindly review when you have bandwidth and let me know if you have further suggestions.
>>>
>>> BTW, I would be happy to help if we decide to add a set of genphy functions for clause 37, although that may mean I need more help/guidance from you :-)
>>
>> You want to have standard clause 37 aneg and this should be generic in phylib.
>> I hacked together a first version that is compile-tested only:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__patchwork.ozlabs.org_patch_1143631_&d=DwICaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=iYElT7HC77pRZ3byVvW8ng&m=ZJArOJvHqNkqvs1x8l9HjfxjCN8e5xJpPz2YViBuKRA&s=EskpfBQtu9IBVeb96dv-sz76xIz4tJK5-lD4-qdIyWI&e= 
>> It supports fixed mode too.
>>
>> It doesn't support half duplex mode because phylib doesn't know 1000BaseX HD yet.
>> Not sure whether half duplex mode is used at all in reality.
>>
>> You could test the new core functions in your own config_aneg and read_status
>> callback implementations.
> 
> Thank you very much for the help! I'm planning to add these functions but I haven't started yet because I'm still going through clause 37 :-)
> 
> Let me apply your patch and run some test on my platform. Will share you results tomorrow.

The patch "net: phy: add support for clause 37 auto-negotiation" works on my CMM platform, with just 1 minor change in phy.h (I guess it's typo?). Thanks again for the help!

-int genphy_c37_aneg_done(struct phy_device *phydev);
+int genphy_c37_config_aneg(struct phy_device *phydev);

BTW, shall I send out my patch v5 now (based on your patch)? Or I should wait till your patch is included in net-next and then send out my patch?


Cheers,

Tao