[PATCH net] net: stmmac: work around sporadic tx issue on link-up

[Heiner Kallweit]

On 24.08.2022 01:22, Jakub Kicinski wrote:
> On Sat, 20 Aug 2022 17:20:37 +0200 Heiner Kallweit wrote:
>> This is a follow-up to the discussion in [0]. It seems to me that
>> at least the IP version used on Amlogic SoC's sometimes has a problem
>> if register MAC_CTRL_REG is written whilst the chip is still processing
>> a previous write. But that's just a guess.
>> Adding a delay between two writes to this register helps, but we can
>> also simply omit the offending second write. This patch uses the second
>> approach and is based on a suggestion from Qi Duan.
>> Benefit of this approach is that we can save few register writes, also
>> on not affected chip versions.
>>
>> This patch doesn't apply cleanly before the commit marked as fixed.
>> There's nothing wrong with this commit.
> 
> I don't think this is right, please do your best to identify where
> the bug was actually introduced and put that in the Fixes tag.
> 
> IIRC this is not the first time you've made this choice so let's
> sort this out, we can bring it up with Greg if you would like,
> I don't see it clarified in the docs.
> 
> My understanding and experience doing backports for my employer is 
> that cutting off the Fixes tag at the place patch application fails 
> is very counter productive. Better to go too far back and let 
> the person maintaining the tree decide if the backport is needed.
> 
OK, I changed the Fixes tag accordingly and submitted a v2.