Re: [PATCH net-next 5/6] r8169: change type of driver_data

[David Miller <davem@davemloft.net>]

From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Sat, 24 Mar 2018 23:18:25 +0100

> Several functions accessing the device driver_data field don't need the
> net_device. All needed parameters can be accessed via struct
> rtl8169_private, therefore change type of driver_data accordingly.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

This doesn't work.

The pci_set_drvdata() call happens after register_netdevice().

At the exact moment register_netdevice() is called, any part of the
driver can be invoked before it returns.

Therefore this change will result in crashes because the drvdata won't
be initialized early enough.

I really think you're taking things too far with the cleanups of this
driver.  It is a reasonably old driver used by a lot of people, and I
think avoiding regressions is 1000 times more important than
"streamlining" control plane functions that have not effect whatsoever
on real driver performance.

Thank you.