On 19/07/2017 19:17, Måns Rullgård wrote:
> Marc Gonzalez writes:
>
>> According to commit e5f3a4a56ce2a707b2fb8ce37e4414dcac89c672
>> ("Documentation: devicetree: clarify usage of the RGMII phy-modes")
>> there are 4 RGMII phy-modes to handle:
>>
>> "rgmii" (RX and TX delays are added by the MAC when required)
>> "rgmii-id" (RGMII with internal RX and TX delays provided by the PHY,
>> the MAC should not add the RX or TX delays in this case)
>> "rgmii-rxid" (RGMII with internal RX delay provided by the PHY,
>> the MAC should not add an RX delay in this case)
>> "rgmii-txid" (RGMII with internal TX delay provided by the PHY,
>> the MAC should not add an TX delay in this case)
>>
>> Let the MAC handle TX clock delay for rgmii and rgmii-rxid.
>>
>> Signed-off-by: Marc Gonzalez <marc_gonza...@sigmadesigns.com>
>> ---
>> drivers/net/ethernet/aurora/nb8800.c | 8 +++++---
>> 1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/aurora/nb8800.c
>> b/drivers/net/ethernet/aurora/nb8800.c
>> index 041cfb7952f8..f3ed320eb4ad 100644
>> --- a/drivers/net/ethernet/aurora/nb8800.c
>> +++ b/drivers/net/ethernet/aurora/nb8800.c
>> @@ -609,7 +609,7 @@ static void nb8800_mac_config(struct net_device *dev)
>> mac_mode |= HALF_DUPLEX;
>>
>> if (gigabit) {
>> - if (priv->phy_mode == PHY_INTERFACE_MODE_RGMII)
>> + if (phy_interface_is_rgmii(dev->phydev))
>> mac_mode |= RGMII_MODE;
>>
>> mac_mode |= GMAC_MODE;
>
> This is a separate issue, and the change is obviously correct.
>
>> @@ -1268,11 +1268,13 @@ static int nb8800_tangox_init(struct net_device *dev)
>> break;
>>
>> case PHY_INTERFACE_MODE_RGMII:
>> - pad_mode = PAD_MODE_RGMII;
>> + case PHY_INTERFACE_MODE_RGMII_RXID:
>> + pad_mode = PAD_MODE_RGMII | PAD_MODE_GTX_CLK_DELAY;
>> break;
>>
>> + case PHY_INTERFACE_MODE_RGMII_ID:
>> case PHY_INTERFACE_MODE_RGMII_TXID:
>> - pad_mode = PAD_MODE_RGMII | PAD_MODE_GTX_CLK_DELAY;
>> + pad_mode = PAD_MODE_RGMII;
>> break;
>
> Won't this just make it break in a different set of circumstances?
I don't think so, and here's my reasoning:
AFAIU, the HW block always requires a TX clock delay
(I don't know what the "safe" interval is. PHY adds
2.4 ns, MAC adds ~1 ns, both work.)
RX clock delay seems to be "Don't Care" (tested both
enabled and disabled by PHY)
By "tested", I mean ability to ping remote system.
If phy-mode is RGMII or RGMII_RXID, then don't add
TX clock delay from PHY, therefore add it from MAC.
If phy_mode is RGMII_ID or RGMII_TXID, then do add
TX clock delay from PHY, therefore don't add it from MAC.
What set of circumstances would create an issue?
Regards.
