Hi Andrew, On 11/04/2016 04:11 PM, Andrew Lunn wrote: > On Fri, Nov 04, 2016 at 04:02:24PM +0100, Sebastian Frias wrote: >> The delay can be applied at PHY or MAC level, but since >> PHY drivers will apply the delay at PHY level when using >> one of the "internal delay" declinations of RGMII mode >> (like PHY_INTERFACE_MODE_RGMII_TXID), applying it again >> at MAC level causes issues. >> >> Signed-off-by: Sebastian Frias <s...@laposte.net> >> --- >> drivers/net/ethernet/aurora/nb8800.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/aurora/nb8800.c >> b/drivers/net/ethernet/aurora/nb8800.c >> index b59aa35..d2855c9 100644 >> --- a/drivers/net/ethernet/aurora/nb8800.c >> +++ b/drivers/net/ethernet/aurora/nb8800.c >> @@ -1282,7 +1282,7 @@ static int nb8800_tangox_init(struct net_device *dev) >> break; >> >> case PHY_INTERFACE_MODE_RGMII_TXID: >> - pad_mode = PAD_MODE_RGMII | PAD_MODE_GTX_CLK_DELAY; >> + pad_mode = PAD_MODE_RGMII; >> break; > > How many boards use this Ethernet driver? How many boards are your > potentially breaking, because they need this delay? >
This part is specific to the Tango architecture, as noted by the function name "nb8800_tangox_init". Also the register used here is Sigma-specific (i.e.: not related to the Aurora VLSI MAC, "au-nb8800") The thing is that without this patch if we set phy-connection-type="rgmii-txid" on the DT, then both, the PHY and the MAC, will apply the delay. Best regards, Sebastian > I guess it is a small number, because doesn't it require the PHY is > also broken, not adding a delay when it should? > > Andrew >
