Re: [PATCH net 2/3] net: dsa: mt7530: move lowering TRGMII driving to mt7530_setup()

Arınç ÜNAL arinc.unal at arinc9.com
Tue Apr 4 12:37:22 PDT 2023


On 26 March 2023 21:13:49 GMT+03:00, "Landen Chao (趙皎宏)" <Landen.Chao at mediatek.com> wrote:
>On Mon, 2023-03-20 at 22:05 +0300, arinc9.unal at gmail.com wrote:
>> 
>> I asked this before, MT7530 DSA driver maintainers, please explain
>> the code
>> I mentioned on the second paragraph.
>> 
>> ---
>> @@ -2207,6 +2198,15 @@ mt7530_setup(struct dsa_switch *ds)
>> 
>>         mt7530_pll_setup(priv);
>> 
>> +       /* Lower Tx driving for TRGMII path */
>> +       for (i = 0; i < NUM_TRGMII_CTRL; i++)
>> +               mt7530_write(priv, MT7530_TRGMII_TD_ODT(i),
>> +                            TD_DM_DRVP(8) | TD_DM_DRVN(8));
>> +
>I guess you ask this part, and I try my best to recall what the
>original author said years ago.
>It is used to adjust the RX delay of port 6 to match the tx
>signal of the link partner.

Ok, thanks for replying. I will move this at the end, inside 'if (trgint)'. Since this doesn't lower the driving, there's no apparent benefit to run this if trgmii is not being used.

Arınç



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