Re: [PATCH net-next] ptp: increase the maximum number of clocks

[David Miller <davem@davemloft.net>]

From: Jiri Benc <jbenc@redhat.com>
Date: Thu, 21 Mar 2013 20:24:19 +0100

> As network adapters supporting PTP are becoming more common, machines with
> many NICs suddenly have many PHCs, too. Although the PHCs are not used in
> such cases, they produce error messages like this:
> 
> igb 0000:07:00.0: ptp_clock_register failed
> 
> Currently, the maximum number of devices accepted by ptp_clock_register
> is 8 which is pretty low. We could silence the error messages but this would
> hurt in case somebody wants to use one of the interfaces to actually run
> PTP, as the /dev/ptp%d device for the desired interface may or may not be
> available after each boot.
> 
> Let's increase the maximum to 128. This shouldn't be a problem, as for the
> char devices, the whole major number is reserved anyway, and 128bit bitmap
> isn't a big deal, either.
> 
> Signed-off-by: Jiri Benc <jbenc@redhat.com>

This really needs to be dynamic, and it shows what a bad idea it was
to use character drivers for this which introduces arbitrary device
arity limitations.

I want to see a better solution to this problem than just bumping this
limit arbitrarily every once in a while.

I'm not apply this patch, we're better than this.