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

[Klara Modin <klarasmodin@gmail.com>]

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.

> >
> > 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