[PATCH] Fix genphy_restart_aneg() for Micrel's ksz9031.

[Guillermo Rodriguez Garcia]

Hi Sascha,

2016-06-14 8:39 GMT+02:00 Sascha Hauer <s.hauer at pengutronix.de>:
> Hi Guillermo,
>
> On Mon, Jun 13, 2016 at 07:29:15PM +0200, Guillermo Rodriguez Garcia wrote:
>> From: grodriguez <guille.rodriguez at gmail.com>
>>
>> Commit da89ee8f2e04 ("Center FLP timing at 16ms") breaks
>> genphy_restart_aneg() for Micrel's ksz9031. According to the
>> datasheet, the ksz9031 requires a wait of 1ms after clearing
>> the PDOWN bit and before read/write access to any PHY registers.
>> ---
>>  drivers/net/phy/phy.c |    9 ++++++++-
>>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> I must say that I am not overly happy with this patch as it leaks in phy
> specific stuff into a somewhat generic function. Anyway, I see the need
> for this patch and so I applied it.

Yes, I understand perfectly and I feel the same.
The alternative was to create a custom genphy_restart_aneg for micrel
PHYs only add the delay there, however I am not sure it is worth the
trouble just for a 1ms delay which will be virtually unnoticeable
anyway.

Also I am not completely sure that this only applies to Micrel. See
this for example in the SMSC911x driver from the Linux kernel:
http://lxr.free-electrons.com/source/drivers/net/ethernet/smsc/smsc911x.c#L1364

Anyway if you would prefer this to be moved to micrel.c I would be
happy to prepare a patch for that; just let me know.

Thank you,

Guillermo Rodriguez Garcia
guille.rodriguez at gmail.com