netdev - Re: [PATCH net-next 0/3] net: phy: Support enabling clocks prior to bus probe

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Date:   Thu, 3 Sep 2020 21:04:11 -0700
From:   Florian Fainelli <f.fainelli@...il.com>
To:     netdev@...r.kernel.org
Cc:     andrew@...n.ch, adam.rudzinski@....net.pl, m.felsch@...gutronix.de,
        hkallweit1@...il.com, richard.leitner@...data.com,
        zhengdejin5@...il.com, devicetree@...r.kernel.org,
        kernel@...gutronix.de, kuba@...nel.org, robh+dt@...nel.org
Subject: Re: [PATCH net-next 0/3] net: phy: Support enabling clocks prior to
 bus probe



On 9/2/2020 9:39 PM, Florian Fainelli wrote:
> Hi all,
> 
> This patch series takes care of enabling the Ethernet PHY clocks in
> DT-based systems (we have no way to do it for ACPI, and ACPI would
> likely keep all of this hardware enabled anyway).
> 
> Please test on your respective platforms, mine still seems to have
> a race condition that I am tracking down as it looks like we are not
> waiting long enough post clock enable.
> 
> The check on the clock reference count is necessary to avoid an
> artificial bump of the clock reference count and to support the unbind
> -> bind of the PHY driver. We could solve it in different ways.
> 
> Comments and test results welcome!

Andrew, while we figure out a proper way to support this with the Linux 
device driver model, would you be opposed in a single patch to 
drivers/net/mdio/mdio-bcm-unimac.c which takes care of enabling the 
PHY's clock during bus->reset just for the sake of getting those systems 
to work, and later on we move over to the pre-probe mechanism?

That would allow me to continue working with upstream kernels on these 
systems without carrying a big pile of patches.
-- 
Florian