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

[Paolo Abeni <pabeni@redhat.com>]

On 7/17/26 12:13 PM, Michael Walle wrote:
> On Fri Jul 17, 2026 at 12:01 PM CEST, Paolo Abeni wrote:
>> On 7/10/26 4:47 PM, Michael Walle wrote:
>>> 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).
>> FTR, sashiko suspect this patch will broke such setup:
>> https://sashiko.dev/#/patchset/20260710143430.2276141-1-mwalle%40kernel.org
> 
> I've seen that, but.. that was the actual change between v1 and v2
> as suggested by Sean. It does not depend on the actual link speed,
> but the maximum link speed. So it is not relevant if the link
> negotiates to a slower speed or not. At least that now matches the
> behavior prior to the phylink conversion. If that was working -
> that I can't tell you.

I'm sorry, following all cross revision discussion is a bit hard here.

I don't understand if the 'link never established' is specific of your
board, or it a constant with this driver. Could you please clarify?

/P