Re: [PATCH net-next 05/15] net: dsa: mt7530: improve code path for setting up port 5

Arınç ÜNAL
2023-12-02T08:37:13Z

On 18.11.2023 17:41, Russell King (Oracle) wrote:
> On Sat, Nov 18, 2023 at 03:31:55PM +0300, Arınç ÜNAL wrote:
>> There're two code paths for setting up port 5:
>>
>> mt7530_setup()
>> -> mt7530_setup_port5()
>>
>> mt753x_phylink_mac_config()
>> -> mt753x_mac_config()
>> -> mt7530_mac_config()
>> -> mt7530_setup_port5()
>>
>> Currently mt7530_setup_port5() from mt7530_setup() always runs. If port 5
>> is used as a CPU, DSA, or user port, mt7530_setup_port5() from
>> mt753x_phylink_mac_config() won't run. That is because priv->p5_interface
>> set on mt7530_setup_port5() will match state->interface on
>> mt753x_phylink_mac_config() which will stop running mt7530_setup_port5()
>> again.
>>
>> Therefore, mt7530_setup_port5() will never run from
>> mt753x_phylink_mac_config().
>>
>> Address this by not running mt7530_setup_port5() from mt7530_setup() if
>> port 5 is used as a CPU, DSA, or user port. This driver isn't in the
>> dsa_switches_apply_workarounds[] array so phylink will always be present.
>>
>> For the cases of PHY muxing or the port being disabled, call
>> mt7530_setup_port5() from mt7530_setup(). mt7530_setup_port5() from
>> mt753x_phylink_mac_config() won't run when port 5 is disabled or used for
>> PHY muxing as port 5 won't be defined on the devicetree.
>
> ... and this should state why this needs to happen - in other words,
> the commit message should state why is it critical that port 5 is
> always setup.

Actually, port 5 must not always be setup. With patch 7, I explain this
while preventing mt7530_setup_port5() from running if port 5 is disabled.

Arınç