netdev - Re: [PATCH net-next 4/4] net: phy: bcm7xxx: remove getting reference clock

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Date:   Fri, 24 Mar 2023 20:50:04 +0100
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Florian Fainelli <f.fainelli@...il.com>,
        Andrew Lunn <andrew@...n.ch>,
        Russell King - ARM Linux <linux@...linux.org.uk>,
        Jakub Kicinski <kuba@...nel.org>,
        David Miller <davem@...emloft.net>,
        Paolo Abeni <pabeni@...hat.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@...adcom.com>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next 4/4] net: phy: bcm7xxx: remove getting reference
 clock

On 24.03.2023 20:03, Florian Fainelli wrote:
> On 3/24/23 11:05, Heiner Kallweit wrote:
>> Now that getting the reference clock has been moved to phylib,
>> we can remove it here.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
> 
> This is not the reference clock for bcm7xxx this is the SoC internal clock that feeds the Soc internal PHY.

Ah, good to know. Then indeed we may have to allow drivers to disable this feature.

Another aspect: When looking at ba4ee3c05365 "net: phy: bcm7xxx: request and manage GPHY clock"
I stumbled across statement "PHY driver can be probed with the clocks turned off".
I interpret this in a way that dynamic PHY detection doesn't work because the PHY ID
registers aren't accessible before the PHY driver has been loaded and probed. Is this right?
Should the MDIO bus driver enable the clock for the PHY?