[PATCH 1/1] net: phy: Do not do CL22 phy reset before ethernet phy driver probe

[Tom Rini]

On Tue, Aug 05, 2025 at 08:00:29PM +0200, Paul Kocialkowski wrote:
> Hi,
> 
> Le Mon 14 Oct 24, 10:43, Marek Vasut a écrit :
> > On 10/14/24 9:06 AM, Sky Huang wrote:
> > > From: "SkyLake.Huang" <skylake.huang at mediatek.com>
> > > 
> > > Remove unnecessary CL22 phy reset before ethernet phy driver
> > > probe. Lots of ethernet phys requires driver to load firmware.
> > > Before that, CL22 phy reset may lead to malfunction.
> > > 
> > > Signed-off-by: SkyLake.Huang <skylake.huang at mediatek.com>
> > > ---
> > >   drivers/net/phy/phy.c | 2 --
> > >   1 file changed, 2 deletions(-)
> > > 
> > > diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> > > index 716a1d46111..e6fed8c41d7 100644
> > > --- a/drivers/net/phy/phy.c
> > > +++ b/drivers/net/phy/phy.c
> > > @@ -839,8 +839,6 @@ struct phy_device *phy_find_by_mask(struct mii_dev *bus, uint phy_mask)
> > >   static void phy_connect_dev(struct phy_device *phydev, struct udevice *dev,
> > >   			    phy_interface_t interface)
> > >   {
> > > -	/* Soft Reset the PHY */
> > > -	phy_reset(phydev);
> > >   	if (phydev->dev && phydev->dev != dev) {
> > >   		printf("%s:%d is connected to %s.  Reconnecting to %s\n",
> > >   		       phydev->bus->name, phydev->addr,
> > 
> > This needs clarification and likely has to be handled differently. Removing
> > the reset would leave the PHY in potentially undefined state.
> > 
> > Which PHY is affected by this ?
> 
> Good hunch. I just bisected down to this commit as I had some issues with my
> Allwinner V3 board using the internal CL22 PHY. The symptom is that the LEDS's
> polarity was inverted. Network still seems to work (although not tested beyond
> ping).
> 
> This change can have very significant consequences in general, which were not
> explored at all in the commit. This may break many boards that do rely on that
> PHY reset, in various scenarios and for various reasons.
> 
> I think it should be reverted as soon as possible to restore previous behavior.

I'm wondering if anyone has further comments here? If I do go and revert
this what is then going to break on the MediaTek side for example?

-- 
Tom
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