Re: [PATCH net-next v4 RESEND] stmmac: tegra: Add MGBE support

[Jon Hunter <jonathanh@nvidia.com>]

Hi Florian,

On 12/10/2022 05:56, Bhadram Varka wrote:

...

>> You should be modeling this as a proper PCS driver and have a 'pcs-handle'
>> property pointing to it in your Device Tree.
>>
>> The configuration you are doing here is probably working the first time you
>> bring-up the network device but I doubt it works across system
>> suspend/resume states where power to the GMAC and PCS is lost, it also
>> begs the question of which mediums this was tested with and whether
>> dynamic switching of speeds and so on is working?
>> --
> 
> For Tegra234, there is UPHY lanes control logic inside XPCS IP which is memory-mapped IP (not part of the MAC IP).
> mgbe_uphy_lane_bringup performs UPHY lane bring up here. Here MGBE/XPCS works in XFI mode.
> 
> Agree that lane bring down logic is not present interface down/suspend paths. Will update the changes accordingly.
> One more thing is that UPHY lane bring should happen only after the line side link is up. This also will make the changes.
> Please let me know if I miss anything here.


An updated version of this has now been posted [0]. It should have been 
marked as 'V5'. We have tested suspend/resume and verified that it is 
working. We are hoping to get this into Linux v6.2 if not too late. Let 
me know if you have any concerns.

Thanks
Jon

[0] 
https://lore.kernel.org/linux-tegra/20221118075744.49442-1-ruppala@nvidia.com/T/#t

-- 
nvpublic