quoted

Using struct_size() makes me think this is supposed to be a flexible
array? I've never used them myself, but shouldn't be some markup so
the compiler knows priv_len is the len of priv?

Maybe link this?
struct mbx_req_cookie {
....
	int priv_len;
	char priv[] __counted_by(priv_len);
}

Yes, that looks correct.

quoted

quoted

+		return err;
+	}
+	do {
+		err = wait_event_interruptible_timeout(cookie->wait,
+						       cookie->done == 1,
+						       cookie->timeout_jiffes);
+	} while (err == -ERESTARTSYS);

This needs a comment, because i don't understand it.

wait_event_interruptible_timeout return -ERESTARTSYS if it was interrupted
by a signal, which will cause misjudgement about cookie->done is timeout. 
In this case, just wait for timeout.
Maybe comment link this?
/* If it was interrupted by a signal (-ERESTARTSYS), it is not true timeout,
 * just wait again.
 */

But why use wait_event_interruptible_timout() if you are going to
ignore all interrupts, a.k.a. signals? Why not use
wait_event_timeout()?

quoted

quoted

+	if ((1 << lane) & le32_to_cpu(reply.mac_addr.lanes))

BIT(). And normally the & would be the other way around.

Maybe changed link this?
...
if (le32_to_cpu(reply.mac_addr.ports) & BIT(lane))

Yes, that is better.

quoted

What exactly is a lane here? Normally we would think of a lane is
-KR4, 4 SERDES lanes making one port. But the MAC address is a
property of the port, not the lane within a port.

lane is the valid bit in 'reply.mac_addr.ports'.
Maybe change it to 'port', that is more appropriate.

You need to be careful with your terms. I read in another patch, that
there is a dual version and a quad version. I've not yet seen how you
handle this, but i assume they are identical, and appear on the PCI
bus X number of times, and this driver will probe X times, once per
instance. We would normally refer to each instance as an
interface. But this driver also mentions PF, so i assume you also have
VFs? And if you have VF, i assume you have an embedded switch which
each of the VFs are connected to. Each VF would normally be connected
to a port of the switch.

So even though you don't have VF support yet, you should be thinking
forward. In the big picture architecture, what does this lane/port
represent? What do other drivers call it?

quoted

Another example of a bad structure layout. It would of been much
better to put the two u8 after speed.

quoted

+} __packed;

And because this is packed, and badly aligned, you are forcing the
compiler to do a lot more work accessing these members.

Yes, It is bad. But FW use this define, I can only follow the define...
Maybe I can add comment here?
/* Must follow FW define here */ 

No need. When somebody sees __packed, it becomes obvious this is ABI
and cannot be changed. Just think about it for any future extensions
to the firmware ABI.

quoted

quoted

+
+static inline void ability_update_host_endian(struct hw_abilities *abi)
+{
+	u32 host_val = le32_to_cpu(abi->ext_ability);
+
+	abi->e_host = *(typeof(abi->e_host) *)&host_val;
+}

Please add a comment what this is doing, it is not obvious.

Maybe link this?
/* Converts the little-endian ext_ability field to host byte order,
 * then copies the value into the e_host field by reinterpreting the
 * memory as the type of e_host (likely a bitfield or structure that
 * represents the extended abilities in a host-friendly format).
 */

This explains what you are doing, but why? Why do you do this only to
this field? What about all the others?

     Andrew