Re: [PATCH] net: phy: DP83811: Add support for the phy

From: Florian Fainelli <f.fainelli@gmail.com>
To: Dan Murphy <dmurphy@ti.com>, Andrew Lunn <andrew@lunn.ch>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: phy: DP83811: Add support for the phy
Date: Tue, 8 May 2018 10:14:29 -0700	[thread overview]
Message-ID: <cc5acc63-bcb5-2bda-9c9d-fd18e0a7740a@gmail.com> (raw)
In-Reply-To: <f4cfe325-f462-e965-3bd8-629acf460fbf@ti.com>

On 05/08/2018 10:13 AM, Dan Murphy wrote:
> Andrew
> 
> On 05/08/2018 11:49 AM, Andrew Lunn wrote:
>> On Tue, May 08, 2018 at 10:56:55AM -0500, Dan Murphy wrote:
>>> All
>>>
>>> On 05/08/2018 09:11 AM, Dan Murphy wrote:
>>>> Add support for the DP83811 phy by extending
>>>> the DP83822 driver to recognize the PHY IDs.
>>>>
>>>> The DP83811 supports both rgmii and sgmii interfaces.
>>>> There are 2 part numbers for this the DP83811R does not
>>>> reliably support the SGMII interface but the DP83811S will.
>>>>
>>>> There is not a way to differentiate these parts from the
>>>> hardware or register set.  So this is controlled via the DT
>>>> to indicate which phy mode is required.  Or the part can be
>>>> strapped to a certain interface.
>>>>
>>>> Data sheet can be found here:
>>>> http://www.ti.com/product/DP83TC811S-Q1/description
>>>> http://www.ti.com/product/DP83TC811R-Q1/description
>>>>
>>>
>>> I am withdrawing this patch for comment.
>>> Some of the future features have varying register definitions between the DP83811
>>> and DP83822
>>
>> Hi Dan
>>
>> It might be worth talking to the ASIC engineers and the
>> test/qualification engineers. There are sometime undocumented
>> registers for testing. You might be able to identify the exact device
>> from these registers.
>>
> 
> Thanks.  I talked to them prior to submitting this patch about determining which part is on the board.
> I will ping them again and poke a little harder.
> 
> It turns out that we will probably need a new driver for this part anyway as there are
> additional features that need to be supported that the 811 just does not support.
> 
> They want to support Master/Slave configurations.
> The 822 supports fiber and eee while the 811 does not.
> The 811 supports the IEEE802.3bw specific fields in MMD1 and MMD3, which are not in the 822.
> The 811 does not support auto-negotiation on the MDI so all the auto-neg registers are invalid for the 811 but are valid for the 822.
> 
> Our Customer engineers felt that combining these two devices into a single driver may confuse the customer.

Why? Having a single Kconfig option to enable and "automatically"
gaining support for new hardware is nice.
-- 
Florian