Re: [PATCH] usb: gadget: u_ether: Don't warn in gether_setup_name_default()

[Andrzej Pietrasiewicz]

Hi,

W dniu 11.01.2023 o 11:35, Jon Hunter pisze:
> On 10/01/2023 16:31, Andrzej Pietrasiewicz wrote:
> > Hi,
> >
> > Hasn't there been a similar patch already?
>
> There could be, but I was not aware. Do you happen to have a link to it?

Nope, I only rely on my memory, which can obviously be faulty.

> > W dniu 6.01.2023 o 17:17, Jon Hunter pisze:
> > > The function gether_setup_name_default() is called by various USB
> > > ethernet gadget drivers. This function always generates the MAC address
> > > for the ethernet gadget device and always prints a warning when
> > > generating the MAC address. Given that these messages are expected, make
> > > these prints informational instead of warnings.
> > >
> > > Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> > > ---
> > >   drivers/usb/gadget/function/u_ether.c | 4 ++--
> > >   1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/usb/gadget/function/u_ether.c 
> > > b/drivers/usb/gadget/function/u_ether.c
> > > index 8f12f3f8f6ee..c19d66cd1446 100644
> > > --- a/drivers/usb/gadget/function/u_ether.c
> > > +++ b/drivers/usb/gadget/function/u_ether.c
> > > @@ -845,13 +845,13 @@ struct net_device *gether_setup_name_default(const char 
> > > *netname)
> > >       snprintf(net->name, sizeof(net->name), "%s%%d", netname);
> > >       eth_random_addr(dev->dev_mac);
> > > -    pr_warn("using random %s ethernet address\n", "self");
> > > +    pr_info("using random %s ethernet address\n", "self");
> >
> > As far as I can tell this function is called by all Ethernet gadgets,
> > and using random Ethernet addresses is the default behavior for all of them,
> > including legacy gadgets. Why to inform about the default situation happening?
> > So in fact maybe it would be better to eliminate the pr_warn() altogether,
> > instead of replacing it with pr_info()? If the user does not care to
> > explicitly set some non-default address(es), why would she care to know
> > that a randomly selected address has been chosen? Note that learning
> > _what_ specific address has been chosen is perfectly doable without
> > these pr_info() calls.
>
>
> That would be fine with me. This print has been there for a long time and so I 
> figured people wanted some sort of message. I would be happy to remove.

It has. Maybe it's been a mistake?

A properly working driver should be silent. In case of Ethernet gadgets
using random MAC addresses is a proper (and default) behavior.

I think it's worth trying to just remove pr_warn(). Or, at least,
change to pr_debug(), because these messages look more like
debugging messages no regular user should be interested in.

There's also the maintainer who can have his say.

@Greg?

As a side note, there's quite a lot of cleanup needed in gadgets' messaging.

Regards,

Andrzej

> Jon