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

[Vinod Koul]

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 :)

-- 
~Vinod