[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 at linux.intel.com>
>>>> ---
>>>>    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.