Re: [PATCH net v5 4/4] net: phy: dp83640: fix per-bus clock lifetime

[Andrew Lunn <andrew@lunn.ch>]

On Mon, Aug 10, 2026 at 10:15:11PM +0800, xuanqiang.luo@linux.dev wrote:
> From: Xuanqiang Luo <xuanqiang.luo@linux.dev>
> 
> Commit 42e2a9e11a1d ("net: phy: dp83640: improve phydev and driver
> removal handling") moved per-bus clock cleanup from module exit to the
> remove path. This leaves two lifetime problems.
> 
> dp83640_clock_get_bus() publishes a newly allocated clock before the
> driver allocates its per-PHY data and registers the PTP clock. If either
> operation fails, no PHY is bound and the remove callback cannot release
> the clock, leaking the clock and the MII bus device reference.
> 
> The remove path can also free a clock after dropping clock_lock. A
> concurrent probe may already have found the clock under
> phyter_clocks_lock and be waiting for clock_lock, allowing it to acquire
> a freed mutex and access the freed clock.
> 
> Use the PHY package infrastructure for the per-bus clock. PHY packages
> are tracked per MII bus, and the driver uses BROADCAST_ADDR as the
> package key so the DP83640 PHYs on the same bus share the same clock
> storage. Call phy_package_join() during probe and phy_package_leave() on
> probe errors and in remove.

Ah, i missed BROADCAST_ADDR. Looking at ext_write(), either accesses
are broadcast to all devices on the bus, or to the specific PHYs
address. There is no one address which is special. I was expecting to
see calls to __phy_package_write()/__phy_package_read() but those are
not needed.

Overall, using phy_packages has simplified this driver a lot.

Once you fix your email address, feel free to add Reviewed-by: Andrew
Lunn <andrew@lunn.ch>

    Andrew