Re: [Outreachy kernel] [PATCH v2] staging: rtl8192u: r8192U_wx: use netdev_warn() instead of printk()

[Lourdes Pedrajas <lu@pplo.net>]

On Tue, Mar 10, 2020 at 11:15:05PM +0100, Stefano Brivio wrote:
> On Tue, 10 Mar 2020 23:10:18 +0100
> Lourdes Pedrajas <lu@pplo.net> wrote:
> 
> > On Tue, Mar 10, 2020 at 10:43:17PM +0100, Stefano Brivio wrote:
> > > On Tue, 10 Mar 2020 22:26:58 +0100
> > > Lourdes Pedrajas <lu@pplo.net> wrote:
> > >   
> > > > printk() is deprecated, use netdev_warn() instead, which is a message printing
> > > > function for network devices, defined in include/linux/netdevice.h.
> > > > Issue found by checkpatch.
> > > > 
> > > > Signed-off-by: Lourdes Pedrajas <lu@pplo.net>
> > > > ---
> > > > Changes since v1:
> > > >  - Replace message printing function pr_warn with network devices
> > > >    specific, netdev_warn()
> > > > 
> > > >  drivers/staging/rtl8192u/r8192U_wx.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/staging/rtl8192u/r8192U_wx.c b/drivers/staging/rtl8192u/r8192U_wx.c
> > > > index 0118edb0b9ab..58c1a8da7a8d 100644
> > > > --- a/drivers/staging/rtl8192u/r8192U_wx.c
> > > > +++ b/drivers/staging/rtl8192u/r8192U_wx.c
> > > > @@ -588,7 +588,7 @@ static int r8192_wx_set_enc(struct net_device *dev,
> > > >  				hwkey);                 /* KeyContent */
> > > >  
> > > >  		} else {
> > > > -			printk("wrong type in WEP, not WEP40 and WEP104\n");
> > > > +			netdev_warn("wrong type in WEP, not WEP40 and WEP104\n");  
> > > 
> > > Err, wait, did you try to compile this? :)
> > > 
> > > The idea of netdev_warn() is that it prefixes the error message by a
> > > reference to the specific network device, so that one knows what device
> > > is actually giving the problem (let's say you have two of these
> > > adapters on a system, or that you have virtual interfaces, etc.).
> > > 
> > > But for that to happen, it needs a pointer to the appropriate struct
> > > net_device.
> > > 
> > > -- 
> > > Stefano
> > >   
> > Stefano, Julia: oh my bad, I did the worst error: break the compilation! :(
> > It won't happen again!
> > 
> > Will search wich function is correct here.
> 
> The one you already found, that part was correct. :)
> 
> -- 
> Stefano
> 
Indeed, also found dev_warn and dev_printk functions, but they are
similar, they expect a pointer to a network device. Also thank for your
explanation, I re-read those functions and now makes me sense.

Lourdes