On Thu, Sep 23, 2021 at 07:30:04PM +0200, Greg Kroah-Hartman wrote:

It fixes the real problem where drivers were making the wrong assumption
that if they registered a device, it would be instantly bound to a
driver.  Drivers that did this were getting lucky, as this was never a
guarantee of the driver core (think about if you enabled async
probing, and the mess with the bus specific locks that should be
preventing much of this)

Since commit d173a137c5bd ("driver-core: enable drivers to opt-out of
async probe") it is possible to opt out of async probing, and PHY
drivers do opt out of it, at the time of writing.