On Tue, Jun 28, 2022 at 02:26:43PM +0200, Hans S wrote:

quoted

Dumb question: if you only flush the locked entries at fast age if the
port is locked, then what happens with the existing locked entries if
the port becomes unlocked before an FDB flush takes place?
Shouldn't mv88e6xxx_port_set_lock() call mv88e6xxx_atu_locked_entry_flush()
too?

That was my first thought too, but the way the flags are handled with the mask etc, does so that
mv88e6xxx_port_set_lock() is called when other flags change. It could be done by the transition
from locked->unlocked by checking if the port is locked already.

Why does mv88e6xxx_port_set_lock() get called when other flags change?

On the other hand, the timers will timeout and the entries will be removed anyhow.

quoted

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+static void mv88e6xxx_atu_locked_entry_timer_work(struct atu_locked_entry *ale)

Please find a more adequate name for this function.

Any suggestions?

Not sure. It depends on whether you leave just the logic to delete a
locked ATU entry, or also the switchdev FDB_DEL_TO_BRIDGE notifier.
In any case, pick a name that reflects what it does. Something with
locked_entry_delete() can't be too wrong.

quoted

From the discussion with Ido and Nikolay I get the impression that
you're not doing the right thing here either, notifying a
SWITCHDEV_FDB_DEL_TO_BRIDGE from what is effectively the
SWITCHDEV_FDB_DEL_TO_DEVICE handler (port_fdb_del).

Hmm, my experience tells me that much is opposite the normal
conventions when dealing with
locked ports, as there was never switchdev notifications from the
driver to the bridge before, but
that is needed to keep ATU and FDB entries in sync.

On delete you mean? So the bridge signals switchdev a deletion of a
locked FDB entry (as I pointed out, this function gets indirectly called
from port_fdb_del), but it won't get deleted until switchdev signals it
back, is what you're saying?

quoted

Why is the rtnl_unlock() outside the switch statement but the rtnl_lock() inside?
Not to mention, the dsa_port_to_bridge_port() call needs to be under rtnl_lock().

Just a small optimization as I also have another case of the switch
(only one switch case if
you didn't notice) belonging to the next patch set regarding dynamic
ATU entries.

What kind of optimization are you even talking about? Please get rid of
coding patterns like this, sorry.

quoted

Please, no "if (chiplock) mutex_lock()" hacks. Just lockdep_assert_held(&chip->reg_lock),
which serves both for documentation and for validation purposes, ensure
the lock is always taken at the caller (which in this case is super easy)
and move on.

As I am calling the function in if statement checks, it would make
that code more messy, while with
this approach the function can be called from anywhere. I also looked
at having two functions, with
one being a wrapper function taking the lock and calling the other...

There are many functions in mv88e6xxx that require the reg_lock to be
held, there's nothing new or special here.

quoted

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+
+     if (mv88e6xxx_port_read(chip, port, MV88E6XXX_PORT_CTL0, &reg))
+             goto out;

It would be good to actually propagate the error to the caller and
"locked" via a pass-by-reference bool pointer argument, not just say
that I/O errors mean that the port is unlocked.

Again the wish to be able to call it from if statement checks,.

quoted

quoted

+     reg &= MV88E6XXX_PORT_ASSOC_VECTOR_PAV_MASK;
+     if (locked) {
+             reg |= MV88E6XXX_PORT_ASSOC_VECTOR_IGNORE_WRONG |
+                     MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT |
+                     MV88E6XXX_PORT_ASSOC_VECTOR_INT_AGE_OUT |
+                     MV88E6XXX_PORT_ASSOC_VECTOR_HOLD_AT_1;

I'd suggest aligning these macros vertically.

They are according to the Linux kernel coding standard wrt indentation afaik.

Compare:

		reg |= MV88E6XXX_PORT_ASSOC_VECTOR_IGNORE_WRONG |
			MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT |
			MV88E6XXX_PORT_ASSOC_VECTOR_INT_AGE_OUT |
			MV88E6XXX_PORT_ASSOC_VECTOR_HOLD_AT_1;

with:

		reg |= MV88E6XXX_PORT_ASSOC_VECTOR_IGNORE_WRONG |
		       MV88E6XXX_PORT_ASSOC_VECTOR_LOCKED_PORT |
		       MV88E6XXX_PORT_ASSOC_VECTOR_INT_AGE_OUT |
		       MV88E6XXX_PORT_ASSOC_VECTOR_HOLD_AT_1;