Re: [PATCH net v2] net: dpaa: fix mode setting

["Michael Walle" <mwalle@kernel.org>]

On Fri Jul 10, 2026 at 4:39 PM CEST, Sean Anderson wrote:
> On 7/10/26 10:22, Michael Walle wrote:
>> Before converting to the phylink interface, the init function would have
>> set the correct I/F mode depending on the maximum link speed of an
>> interface. After converting to phylink, the established link speed
>> is used to determine this setting and is set in the .link_up()
>> callback. The callback isn't called because the link is never
>> established between the PCS and a connected SGMII PHY.
>> To fix it, don't use the current speed, but set the mode depending on
>> the interface (which implies the maximum speed) in .mac_config().
>> 
>> Fixes: 5d93cfcf7360 ("net: dpaa: Convert to phylink")
>> Suggested-by: Sean Anderson <sean.anderson@linux.dev>
>> Signed-off-by: Michael Walle <mwalle@kernel.org>
>> ---
>> FWIW, I dropped setting a non-reserved mode in init(). The hardware
>> default is 0 and the mac_config() will set a valid mode anyway.
>> 
>> Changes in v2:
>>   - the setting is/was based on the maximum speed, not the current
>>     speed. thus, move the setting into mac_config().
>>   - Link to v1: https://lore.kernel.org/r/20260706121011.1948906-1-mwalle@kernel.org/
>> 
>>   .../net/ethernet/freescale/fman/fman_dtsec.c  | 26 ++++++++++---------
>>   1 file changed, 14 insertions(+), 12 deletions(-)
>> 
>> diff --git a/drivers/net/ethernet/freescale/fman/fman_dtsec.c b/drivers/net/ethernet/freescale/fman/fman_dtsec.c
>> index fe35703c509e..7075f93bab49 100644
>> --- a/drivers/net/ethernet/freescale/fman/fman_dtsec.c
>> +++ b/drivers/net/ethernet/freescale/fman/fman_dtsec.c
>> @@ -900,22 +900,28 @@ static void dtsec_mac_config(struct phylink_config *config, unsigned int mode,
>>   {
>>   	struct mac_device *mac_dev = fman_config_to_mac(config);
>>   	struct dtsec_regs __iomem *regs = mac_dev->fman_mac->regs;
>> -	u32 tmp;
>> +	u32 ecntrl, maccfg2;
>> +
>> +	maccfg2 = ioread32be(&regs->maccfg2);
>> +	maccfg2 &= ~(MACCFG2_NIBBLE_MODE | MACCFG2_BYTE_MODE);
>>   
>>   	switch (state->interface) {
>>   	case PHY_INTERFACE_MODE_RMII:
>> -		tmp = DTSEC_ECNTRL_RMM;
>> +		ecntrl = DTSEC_ECNTRL_RMM;
>> +		maccfg2 |= MACCFG2_NIBBLE_MODE;
>>   		break;
>>   	case PHY_INTERFACE_MODE_RGMII:
>>   	case PHY_INTERFACE_MODE_RGMII_ID:
>>   	case PHY_INTERFACE_MODE_RGMII_RXID:
>>   	case PHY_INTERFACE_MODE_RGMII_TXID:
>> -		tmp = DTSEC_ECNTRL_GMIIM | DTSEC_ECNTRL_RPM;
>> +		ecntrl = DTSEC_ECNTRL_GMIIM | DTSEC_ECNTRL_RPM;
>> +		maccfg2 |= MACCFG2_BYTE_MODE;
>>   		break;
>>   	case PHY_INTERFACE_MODE_SGMII:
>>   	case PHY_INTERFACE_MODE_1000BASEX:
>>   	case PHY_INTERFACE_MODE_2500BASEX:
>> -		tmp = DTSEC_ECNTRL_TBIM | DTSEC_ECNTRL_SGMIIM;
>> +		ecntrl = DTSEC_ECNTRL_TBIM | DTSEC_ECNTRL_SGMIIM;
>> +		maccfg2 |= MACCFG2_BYTE_MODE;
>>   		break;
>>   	default:
>>   		dev_warn(mac_dev->dev, "cannot configure dTSEC for %s\n",
>> @@ -923,7 +929,8 @@ static void dtsec_mac_config(struct phylink_config *config, unsigned int mode,
>>   		return;
>>   	}
>>   
>> -	iowrite32be(tmp, &regs->ecntrl);
>> +	iowrite32be(ecntrl, &regs->ecntrl);
>> +	iowrite32be(maccfg2, &regs->maccfg2);
>>   }
>>   
>>   static void dtsec_link_up(struct phylink_config *config, struct phy_device *phy,
>> @@ -948,15 +955,10 @@ static void dtsec_link_up(struct phylink_config *config, struct phy_device *phy,
>>   	iowrite32be(tmp, &regs->ecntrl);
>>   
>>   	tmp = ioread32be(&regs->maccfg2);
>> -	tmp &= ~(MACCFG2_NIBBLE_MODE | MACCFG2_BYTE_MODE | MACCFG2_FULL_DUPLEX);
>> -	if (speed >= SPEED_1000)
>> -		tmp |= MACCFG2_BYTE_MODE;
>> -	else
>> -		tmp |= MACCFG2_NIBBLE_MODE;
>> -
>>   	if (duplex == DUPLEX_FULL)
>>   		tmp |= MACCFG2_FULL_DUPLEX;
>> -
>> +	else
>> +		tmp &= ~MACCFG2_FULL_DUPLEX;
>
> Did you test this when forcing 10/100 speed?

No I didn't. Well I can't. I have a very weird board which only
supports 1000base-X (and copper SFPs in 1000basex autoneg mode). On
top of that there is a Marvell 88E1112 in between the SFP and the
MAC, for which the PHY driver is completely broken. Long story
short, I'm not able to test that (yet/at all? Not sure).

-michael

>
>>   	iowrite32be(tmp, &regs->maccfg2);
>>   
>>   	mac_dev->update_speed(mac_dev, speed);
>
> If so,
>
> Reviewed-by: Sean Anderson <sean.anderson@linux.dev>