Re: [Intel-wired-lan] [PATCH] igb: support BCM54616 PHY

[Florian Fainelli <f.fainelli@gmail.com>]

On 07/27/2017 08:37 AM, Andrew Lunn wrote:
> On Thu, Jul 27, 2017 at 12:40:01AM +0000, Brown, Aaron F wrote:
>>> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On Behalf
>>> Of John W. Linville
>>> Sent: Friday, July 21, 2017 11:12 AM
>>> To: netdev@vger.kernel.org
>>> Cc: intel-wired-lan@lists.osuosl.org; John W. Linville
>>> <linville@tuxdriver.com>
>>> Subject: [Intel-wired-lan] [PATCH] igb: support BCM54616 PHY
>>>
>>> The management port on an Edgecore AS7712-32 switch uses an igb MAC,
>>> but
>>> it uses a BCM54616 PHY. Without a patch like this, loading the igb
>>> module produces dmesg output like this:
>>>
>>> [    3.439125] igb: Copyright (c) 2007-2014 Intel Corporation.
>>> [    3.439866] igb: probe of 0000:00:14.0 failed with error -2
>>>
>>> Signed-off-by: John W. Linville <linville@tuxdriver.com>
>>> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
>>> ---
>>>  drivers/net/ethernet/intel/igb/e1000_82575.c   | 6 ++++++
>>>  drivers/net/ethernet/intel/igb/e1000_defines.h | 1 +
>>>  drivers/net/ethernet/intel/igb/e1000_hw.h      | 1 +
>>>  3 files changed, 8 insertions(+)
>>
>> I do not have the specific hardware (Edgecore switch) but as far as regression tests go this works fine.
>> Tested-by: Aaron Brown <aaron.f.brown@intel.com>
> 
> Sorry, missed the initial post, so replying to a reply.
> 
> Linux has supported the BCM54616 PHY since April 2015. If the Intel
> drivers used the Linux PHY drivers, you would not of had this problem.
> 
> It would be good if somebody spent the time to migrate these MAC
> drivers to use the common Linux PHY infrastructure.

I suspect there is a design pattern within the Intel drivers to share as
much low-level code as possible between OSes and only have some
Linux-ism where necessary (e.g: net_device, ethtool etc.).

PHY code is a pain in general, especially if you are serious about
testing interoperability (which is where you can spend tons of $$$ with
little reward but just say: yes it works), so it may make sense to share
it across different OSes.

I too, wish there was more sharing, but considering that this works for
the Intel driver, there is little incentive in doing this I suppose...
-- 
Florian