Re: [PATCH 1/2] hwmon: (ibmpowernv) Quieten when probing finds no device

[Neelesh Gupta]

On 10/31/2014 06:51 PM, Guenter Roeck wrote:
> On 10/31/2014 02:41 AM, Jean Delvare wrote:
> > Hi Michael,
> >
> > On Fri, 31 Oct 2014 17:45:22 +1100, Michael Ellerman wrote:
> > > Because we build kernels with drivers built in for many platforms, it's
> > > normal for the ibmpowernv driver to be loaded on systems that don't 
> > > have
> > > the appropriate hardware.
> > >
> > > Currently the driver spams the log with:
> > >
> > >    ibmpowernv ibmpowernv.0: Opal node 'sensors' not found
> > >    ibmpowernv: Platfrom driver probe failed
> > >
> > > But there is no error, this machine is not a powernv and doesn't have
> > > the hardware. So change the sensors message to dev_dbg(), and only 
> > > print
> > > an error about the probe failing if it's not ENODEV.
> > >
> > > Also fix the spelling of "Platfrom" and print the actual error value.
> > >
> > > Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> > > ---
> > >   drivers/hwmon/ibmpowernv.c | 6 ++++--
> > >   1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
> > > index d2bf2c97ae70..6a30eeea94be 100644
> > > --- a/drivers/hwmon/ibmpowernv.c
> > > +++ b/drivers/hwmon/ibmpowernv.c
> > > @@ -181,7 +181,7 @@ static int __init populate_attr_groups(struct 
> > > platform_device *pdev)
> > >
> > >       opal = of_find_node_by_path("/ibm,opal/sensors");
> > >       if (!opal) {
> > > -        dev_err(&pdev->dev, "Opal node 'sensors' not found\n");
> > > +        dev_dbg(&pdev->dev, "Opal node 'sensors' not found\n");
> > >           return -ENODEV;
> > >       }
> > >
> > > @@ -335,7 +335,9 @@ static int __init ibmpowernv_init(void)
> > >
> > >       err = platform_driver_probe(&ibmpowernv_driver, 
> > > ibmpowernv_probe);
> > >       if (err) {
> > > -        pr_err("Platfrom driver probe failed\n");
> > > +        if (err != -ENODEV)
> > > +            pr_err("Platform driver probe failed (%d)\n", err);
> > >
> > >           goto exit_device_del;
> > >       }
> >
> > Looks reasonable.
> The reduced noise, ok, but a better fix would be to not attempt to load
> the driver in the first place. This should be doable by introducing an
> of_match_table.

The parent 'sensors' node doesn't have a compatible property, rather 
individual
child sensors have. So, instead we can introduce 
'platform_driver.id_table' for
the probe.

Thanks,
Neelesh

> Guenter
>
> > Reviewed-by: Jean Delvare <jdelvare@xxxxxxx>

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