[PATCH] i2c: designware: do not show SDA hold time warning when not needed

[Jarkko Nikula]

On 04/18/2017 10:59 AM, Thomas Petazzoni wrote:
> Hello,
>
> On Tue, 18 Apr 2017 10:54:47 +0300, Andy Shevchenko wrote:
>> On Fri, 2017-04-14 at 22:53 +0200, Thomas Petazzoni wrote:
>>> When the I2C controller IP block has a revision too old to be able to
>>> configure the SDA hold time, the driver currently displays a
>>> warning. However, it does so unconditionally, even if no SDA hold time
>>> has been configured through the Device Tree. This causes useless
>>> warnings when running the system, so only show the warning if a SDA
>>> hold time was specified.
>>
>> As far as I understand the warning it would be better to keep it in
>> either way, though you may shift it to debug level.
>>
>> Wolfram, Jarkko, thoughts?
>
> Why show a message when the user has not requested a custom SDA hold
> time? Getting a warning about something you haven't requested seems
> really odd.
>
> I think it makes a lot more sense to keep it at the warning level
> (because it's important to get this message if you configure a custom
> SDA hold time), but only show it when appropriate.
>
I guess warning over debug level could have slightly better chance to 
prevent someone not adding needless "i2c-sda-hold-time-ns" property in a 
hardware that doesn't support SDA hold time. But needless spamming have 
negative value so this is worth to fix. (I would do this as a single 
liner by else if ()).

Acked-by: Jarkko Nikula <jarkko.nikula at linux.intel.com>