Re: [PATCH net-next 2/2] net: mctp: Add MCTP USB transport driver

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Feb 07, 2025 at 05:45:33PM +0800, Jeremy Kerr wrote:
> Hi Greg,
> 
> > > > > +               dev_err(&mctp_usb->usbdev->dev, "%s: urb status: %d\n",
> > > > > +                       __func__, status);
> > > > 
> > > > This could flood the logs, are you sure you need it at dev_err()
> > > > level?
> > > > 
> > > > And __func__ is redundant, it's present in dev_*() calls already.
> > > 
> > > am I missing something then?
> > > 
> > >    [  146.130170] usb 2-1: short packet (hdr) 6
> > > 
> > > emitted from:
> > > 
> > >     dev_dbg(&mctp_usb->usbdev->dev,
> > >             "short packet (hdr) %d\n",
> > >             hdr->len);
> > > 
> > > Seems like we get the driver name, but not the function.
> > > 
> > > I'm happy to remove the __func__ output either way, but I will also
> > > make the logs a little more descriptive for context, if we don't have
> > > func data.
> > 
> > Please read Documentation/admin-guide/dynamic-debug-howto.rst, it shows
> > how to get the function information from the dev_dbg() lines at runtime.
> > 
> > In short:
> >         $ alias ddcmd='echo $* > /proc/dynamic_debug/control'
> >         # add function to all enabled messages
> >         $ ddcmd '+f'
> 
> Your original comment was on the dev_err() call though (sorry, I've
> complicated the discussion by using a dev_dbg() example).

Sorry, I got confused here too, I saw it on dev_dbg() calls in my
review.

> Looks like only dev_dbg (and not _err/_warn/etc) has provision for
> __func__, is that right?

Yes.

> I've since removed the __func__ references anyway, and replaced with
> better context on the messages, but keen to make sure I have the correct
> understanding in general.

That sounds better, avoiding __func__ wherever possible is usually a
good idea.

thanks,

gre gk-h