phy_connect_dev calling phy_reset???

Tim Harvey tharvey at
Thu Mar 3 17:00:10 CET 2022

On Mon, Feb 28, 2022 at 12:01 PM Tim Harvey <tharvey at> wrote:
> Greetings,
> I'm wondering if it is proper in U-Boot for phy_connect_dev() to
> always call phy_reset() which generates a soft reset via BMCR_RESET.
> For some (or most?) PHY's this resets specific PHY config such as
> RGMII delays and LED configuration that may have been configured by
> firmware running prior to U-Boot (SPL/TPL).
> I believe there was some discussion and thrash about this in the Linux
> kernel in the past and while I can't find the discussion or patches I
> see that for the current kernel BMCR_RESET is in genphy_soft_reset
> which() is not called in the generic phy_connect() but instead only
> called by a handful of phy drivers which I would expect is ok as those
> phy drivers would also be re-configuring the PHY.
> Specifically I have an issue with this with a board that has custom
> firmware code that runs prior to U-Boot and the BMCR reset is undoing
> specific PHY config that I've done in this firmware causing me to look
> at implementing PHY drivers in U-Boot that otherwise would not be
> needed.

Joe and Ramon,

Do you have any comment on removing the call to phy_reset in
phy_connect_dev? Linux delegates calling genphy_soft_reset to the phy
drivers that need to whereas U-Boot seems to take the opposite
approach requireing a phy driver to set PHY_FLAG_BROKEN_RESET to skip
the reset. I think U-Boot should follow Linux and not perform a reset
without a PHY driver specifically needing it.

Best regards,


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