[U-Boot] [PATCH] net: macb: sama5d4 is not gigabit capable

[Andreas Bießmann]

Hi Gregory,

On 16.12.2015 10:32, Gregory CLEMENT wrote:
> Hi Joe,
>  
>  On mar., déc. 15 2015, Joe Hershberger <joe.hershberger at gmail.com> wrote:
> 
>> Hi Gregory,
>>
>> On Mon, Dec 14, 2015 at 10:37 AM, Gregory CLEMENT
>> <gregory.clement at free-electrons.com> wrote:
>>> During the initialization of PHY the gigabit bit capable is set if the
>>> controller is a GEM. However, for sama5d4, the GEM is not gigabit
>>> capable. Improperly setting the GBE capability leads to an unresponsive
>>> MAC controller. This patch fix this behavior allowing to use the gmac
>>> with the sama5d4.
>>>
>>> Suggested-by: Nicolas Ferre <nicolas.ferre at atmel.com>
>>> Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
>>> ---
>>>  drivers/net/macb.c | 7 +++++--
>>>  1 file changed, 5 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/net/macb.c b/drivers/net/macb.c
>>> index a5c1880..642717d 100644
>>> --- a/drivers/net/macb.c
>>> +++ b/drivers/net/macb.c
>>> @@ -480,8 +480,11 @@ static int macb_phy_init(struct macb_device *macb)
>>>                 return 0;
>>>         }
>>>
>>> -       /* First check for GMAC */
>>> -       if (macb_is_gem(macb)) {
>>> +       /* 
>>> +        * First check for GMAC, but not the one on SAMA5D4 which is
>>> +        * not gigabit capabale
>>> +        */
>>> +       if (macb_is_gem(macb) && ! cpu_is_sama5d4()) {
>>
>> Is there not some other property that can identify the lack of Gigabit
>> support in the "GEM"? It would be better to not have to keep track of
>> the next processor and the one after that which has the same
>> situation.
> 
> I agree and I started to looked for this kind of information. But there
> is not such information documented inside the controller. I also think
> of the controller ID but I doubt that there is a link between the
> gigabit capability and the version of the GEM. On sama5d3 the revision is
> 0x119 and the one in sama5d4 is 0x120, so this really reflects the
> version of the controller itself and not his capabilities.

You where faster ... answer my question before I was asking, at least to
the timestamp of the mail ;)

> I also had a look on how it was done in the kernel, and they relies on
> the compatible string which is different for each SoC.

We will get this also if the network detection has moved to DM completely.

> Last thing, but it is only speculation, I think that the gigabit
> capability depend on the SoC around the controller and not the
> controller itself. Being able to do gigabit means being able to have
> high speed dedicated lines and it is out of the scope of the controller
> itself. An other hint is actually the fact that we have to set this GBE
> bit in the configuration register of the controller, for me that means
> that the controller is not aware of it.

Good point. So could we please patch the macb_is_gem() then? I think we
should also add the sama5d2 as Nicolas said this has also no GiB capability.

Andreas

> 
> Thanks,
> 
> Gregory
> 
>>
>>>                 lpa = macb_mdio_read(macb, MII_STAT1000);
>>>
>>>                 if (lpa & (LPA_1000FULL | LPA_1000HALF)) {
>>> --
>>> 2.5.0
>>>
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>