Re: [PATCH 3/3] net-next: mediatek: add RX delay support

From: John Crispin
Date: Thu May 05 2016 - 13:37:49 EST




On 05/05/2016 14:13, Andrew Lunn wrote:
> On Thu, May 05, 2016 at 11:17:36AM +0200, John Crispin wrote:
>> If an external Gigabit PHY is connected to either of the MACs we need to
>> tell the to use a RX delay. Not doing so will result in heavy packet loss
>> and/or data corruption of RX traffic.
>
> Hi John
>
> Is this comment correct? Reading the code, all this switch statement
> does is select between RGMII, MII and RMII. It has nothing to do with
> delay. I suspect the PHY is doing the delay, not the MAC, since you
> pass the phy mode to of_phy_connect().
>
> If my interpretation of the code is correct, you might also want to
> handle PHY_INTERFACE_MODE_RGMII_TXID and PHY_INTERFACE_MODE_RGMII_ID
> which are also RGMII modes.
>
> Andrew

Hi Andrew,

the comment is indeed incorrect and the PHY needs to handle the delay. i
will send a V2 and also add _TXID and _ID

John