Re: [PATCH net v3] ptp: prevent possible ABBA deadlock in ptp_clock_freerun()

[Vladimir Oltean <vladimir.oltean@nxp.com>]

On Mon, Jul 21, 2025 at 08:36:17PM +0900, Jeongjun Park wrote:
> However, I think ptp->n_vclocks_mux also needs to be annotating lock
> subclass because there may be false positives due to recursive locking
> between physical and virtual clocks.

Did you miss the part where I reiterated, in my review comment to your v2,
that after commit 5ab73b010cad ("ptp: fix breakage after ptp_vclock_in_use()
rework"), ptp->n_vclocks_mux is only acquired by physical clocks, not by
virtual clocks?

Also, in general I think it would be useful to include more substantial
pieces of my explanation in your commit message, or link to it in its
entirety. I am worried that the info from it becomes denatured, for
example this piece from your commit message: "Functions like
clock_adjtime() can only be called with physical clocks." I did not say
that, I said that **in order for the clock_adjtime() call to acquire
&ptp->n_vclocks_mux**, then the clock must have been physical.
In general, adjusting a virtual clock is perfectly possible, thus your
restatement is false, and it proves a lack of understanding of the
ptp->n_vclocks_mux locking convention.