Re: [alsa-devel] [PATCH 2/6] soundwire: cadence_master: add hw_reset capability in debugfs

[Pierre-Louis Bossart]

On 9/4/19 11:49 AM, Vinod Koul wrote:
> On 04-09-19, 08:18, Pierre-Louis Bossart wrote:
> > On 9/4/19 2:13 AM, Vinod Koul wrote:
> > > On 13-08-19, 16:32, Pierre-Louis Bossart wrote:
> > > > Provide debugfs capability to kick link and devices into hard-reset
> > > > (as defined by MIPI). This capability is really useful when some
> > > > devices are no longer responsive and/or to check the software handling
> > > > of resynchronization.
> > > >
> > > > Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> > > > ---
> > > >    drivers/soundwire/cadence_master.c | 20 ++++++++++++++++++++
> > > >    1 file changed, 20 insertions(+)
> > > >
> > > > diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
> > > > index 046622e4b264..bd58d80ff636 100644
> > > > --- a/drivers/soundwire/cadence_master.c
> > > > +++ b/drivers/soundwire/cadence_master.c
> > > > @@ -340,6 +340,23 @@ static int cdns_reg_show(struct seq_file *s, void *data)
> > > >    }
> > > >    DEFINE_SHOW_ATTRIBUTE(cdns_reg);
> > > > +static int cdns_hw_reset(void *data, u64 value)
> > > > +{
> > > > +	struct sdw_cdns *cdns = data;
> > > > +	int ret;
> > > > +
> > > > +	if (value != 1)
> > > > +		return 0;
> > >
> > > Should this not be EINVAL to indicate invalid value passed?
> >
> > Maybe. I must admit I don't know what -EINVAL would do, this is used for
> > debugfs so it's not clear to me if the user will see a difference?
>
> Well user should see "write error: Invalid argument" when he writes
> anything other than valid values :)

ok then, will do.