linux-kernel - Re: [PATCH v2 1/2] net: phylink: init phydev on phylink

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Date:   Mon, 12 Dec 2022 15:20:11 +0000
From:   <Claudiu.Beznea@...rochip.com>
To:     <olteanv@...il.com>
CC:     <Nicolas.Ferre@...rochip.com>, <davem@...emloft.net>,
        <edumazet@...gle.com>, <kuba@...nel.org>, <pabeni@...hat.com>,
        <linux@...linux.org.uk>, <andrew@...n.ch>, <hkallweit1@...il.com>,
        <Sergiu.Moga@...rochip.com>, <netdev@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 1/2] net: phylink: init phydev on phylink_resume()

Hi, Vladimir,

On 12.12.2022 15:54, Vladimir Oltean wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> Hi Claudiu,
> 
> On Mon, Dec 12, 2022 at 01:28:44PM +0200, Claudiu Beznea wrote:
>> There are scenarios where PHY power is cut off on system suspend.
>> There are also MAC drivers which handles themselves the PHY on
>> suspend/resume path. For such drivers the
>> struct phy_device::mac_managed_phy is set to true and thus the
>> mdio_bus_phy_suspend()/mdio_bus_phy_resume() wouldn't do the
>> proper PHY suspend/resume. For such scenarios call phy_init_hw()
>> from phylink_resume().
>>
>> Suggested-by: Russell King (Oracle) <linux@...linux.org.uk>
>> Signed-off-by: Claudiu Beznea <claudiu.beznea@...rochip.com>
>> ---
>>
>> Hi, Russel,
>>
>> I let phy_init_hw() to execute for all devices. I can restrict it only
>> for PHYs that has struct phy_device::mac_managed_phy = true.
>>
>> Please let me know what you think.
>>
>> Thank you,
>> Claudiu Beznea
>>
>>
>>  drivers/net/phy/phylink.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
>> index 09cc65c0da93..6003c329638e 100644
>> --- a/drivers/net/phy/phylink.c
>> +++ b/drivers/net/phy/phylink.c
>> @@ -2031,6 +2031,12 @@ void phylink_resume(struct phylink *pl)
>>  {
>>       ASSERT_RTNL();
>>
>> +     if (pl->phydev) {
>> +             int ret = phy_init_hw(pl->phydev);
>> +             if (ret)
>> +                     return;
>> +     }
>> +
> 
> If the config_init() method of the driver does things such as this:
> 
>         phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
> 
> like for example the marvell10g.c driver, won't a user-configured manual
> MDI setting get overwritten after a suspend/resume cycle?

I'm not fully sure about it. I have to look further though the code.
At the same time phy_init_hw() is called also on mdio_bus_phy_resume().

Thank you,
Claudiu Beznea

> 
>>       if (test_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state)) {
>>               /* Wake-on-Lan enabled, MAC handling */
>>
>> --
>> 2.34.1
>>