Re: [PATCH net-next 0/4] net: ethtool: Untangle PHYLIB dependency

On Thu, 2 Jul 2020 18:34:24 +0200 Andrew Lunn wrote:

On Thu, Jul 02, 2020 at 05:56:52PM +0200, Michal Kubecek wrote:

quoted

On Wed, Jul 01, 2020 at 09:29:38PM -0700, Florian Fainelli wrote:  

quoted

Hi all,

This patch series untangles the ethtool netlink dependency with PHYLIB
which exists because the cable test feature calls directly into PHY
library functions. The approach taken here is to utilize a new set of
net_device_ops function pointers which are automatically set to the PHY
library variants when a network device driver attaches to a PHY device.  

I'm not sure about the idea of creating a copy of netdev_ops for each
device using phylib. First, there would be some overhead (just checked
my 5.8-rc3 kernel, struct netdev_ops is 632 bytes). Second, there is
quite frequent pattern of comparing dev->netdev_ops against known
constants to check if a network device is of certain type; I can't say
for sure if it is also used with devices using phylib in existing code
but it feels risky.  

I agree with Michal here. I don't like this.

I think we need phylib to register a set of ops with ethtool when it
loads. It would also allow us to clean up phy_ethtool_get_strings(),
phy_ethtool_get_sset_count(), phy_ethtool_get_stats().

+1