Re: [PATCH 1/2] soundwire: add macro to selectively change error levels

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

On 4/1/21 2:24 AM, Vinod Koul wrote:
> On 31-03-21, 09:13, Bard Liao wrote:
>> From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
>>
>> We sometimes discard -ENODATA when reporting errors and lose all
>> traces of issues in the console log, add a macro to add use dev_dbg()
>> in such cases.
>>
>> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
>> Reviewed-by: Rander Wang <rander.wang@intel.com>
>> Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
>> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
>> ---
>>   drivers/soundwire/bus.h | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
>> index 40354469860a..8370216f95d4 100644
>> --- a/drivers/soundwire/bus.h
>> +++ b/drivers/soundwire/bus.h
>> @@ -227,4 +227,12 @@ int sdw_bwrite_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 val
>>   void sdw_clear_slave_status(struct sdw_bus *bus, u32 request);
>>   int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size);
>>   
>> +#define sdw_dev_dbg_or_err(dev, is_err, fmt, ...)			\
>> +	do {								\
>> +		if (is_err)						\
>> +			dev_err(dev, fmt, __VA_ARGS__);			\
>> +		else							\
>> +			dev_dbg(dev, fmt, __VA_ARGS__);			\
>> +	} while (0)
> 
> I see a variant in sof code and now here, why not add in a
> dev_dbg_or_err() and use everywhere?

Good point, I hesitated back and forth on specific v. generic macro.

The main reason why I added this macro for SoundWire is that quite a few 
subsystems have their own debug functions (DRM, ACPI, etc), and I wasn't 
sure if there was any appetite to add more options in 
include/linux/dev_printk.h. SOF also uses a different format due to history.

If at the end of the day SoundWire and SOF are the only users the value 
of a common macro is limited.

But it's true that the macro could be used by others.

I really have no opinion here and will follow the consensus.