Re: [PATCH wireless-next] wifi: mt76: fix of_get_mac_address error handling

["Rosen Penev" <rosenp@gmail.com>]

On Thu Jun 18, 2026 at 4:51 PM PDT, Klara Modin wrote:
> On 2026-06-18 16:01:45 -0700, Rosen Penev wrote:
>> On Thu, Jun 18, 2026 at 2:47 PM Klara Modin <klarasmodin@gmail.com> wrote:
>> >
>> > Hi,
>> >
>> > On 2026-04-26 22:17:46 -0700, Rosen Penev wrote:
>> > > Check return value instead of is_valid_ether_addr. The latter is handled
>> > > by the former.
>> > >
>> > > Signed-off-by: Rosen Penev <rosenp@gmail.com>
>> > > ---
>> > >  drivers/net/wireless/mediatek/mt76/eeprom.c | 2 +-
>> > >  1 file changed, 1 insertion(+), 1 deletion(-)
>> > >
>> > > diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c b/drivers/net/wireless/mediatek/mt76/eeprom.c
>> > > index 93d91264687f..0f6ccf6ed53d 100644
>> > > --- a/drivers/net/wireless/mediatek/mt76/eeprom.c
>> > > +++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
>> > > @@ -93,7 +93,7 @@ mt76_eeprom_override(struct mt76_phy *phy)
>> > >       if (err == -EPROBE_DEFER)
>> > >               return err;
>> > >
>> > > -     if (!is_valid_ether_addr(phy->macaddr)) {
>> > > +     if (err) {
>> > >               eth_random_addr(phy->macaddr);
>> > >               dev_info(dev->dev,
>> > >                        "Invalid MAC address, using random address %pM\n",
>> > > --
>> > > 2.54.0
>> > >
>> >
>> > Recently I have started to see randomized MAC-addresses on my x86 laptop
>> > with a MT7922 and the above message printed in the kernel log. I have
>> > CONFIG_OF turned on, but since this is an ACPI system the device is not
>> > described by any device tree and the earlier of_get_mac_address() likely
>> > fails with -ENODEV. Looking at the !CONFIG_OF stub for
>> > of_get_mac_address it always returns -ENODEV, meaning this will always
>> > randomize the mac in that case too.
>
>> IIRC, the normal device_get_mac_address supports nvmem now. Does that
>> fix your use case?
>
> I tried this:
>
> diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c b/drivers/net/wireless/mediatek/mt76/eeprom.c
> index b99d7452800f..243a8f2c7bda 100644
> --- a/drivers/net/wireless/mediatek/mt76/eeprom.c
> +++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
> @@ -174,10 +174,9 @@ int
>  mt76_eeprom_override(struct mt76_phy *phy)
>  {
>  	struct mt76_dev *dev = phy->dev;
> -	struct device_node *np = dev->dev->of_node;
>  	int err;
>
> -	err = of_get_mac_address(np, phy->macaddr);
> +	err = device_get_mac_address(dev->dev, phy->macaddr);
>  	if (err == -EPROBE_DEFER)
>  		return err;
>
>
> but I still get a random MAC.
Then the original patch should be reverted. Unfortunate that it doesn't
workq
>
>> >
>> > Reverting this patch fixes the issue and the correct MAC address is
>> > used. I'm not sure if there is any case where of_get_mac_addres() could
>> > fail in a way that results in a valid MAC address but it seems unlikely
>> > to me.
>> >
>> > Regards,
>> > Klara Modin