Re: [PATCH 4/7] ASoC: Intel: Skylake: Shield against no-NHLT configurations

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

On 3/9/20 8:03 AM, Cezary Rojewski wrote:
> On 2020-03-06 22:03, Pierre-Louis Bossart wrote:
>>
>>
>>> -    intel_nhlt_free(skl->nhlt);
>>> +    if (skl->nhlt)
>>> +        intel_nhlt_free(skl->nhlt);
>>
>> we could alternatively move the test in intel_nhlt_free, which seems 
>> like a more robust thing to do?
> 
> Depends. In general kernel-internal API trusts its caller and appending 
> 'ifs' everywhere would unnecessarily slow entire kernel down. While 
> intel_nhlt_free is called rarely, I'd still argue caller should be sane 
> about its invocation.
> 
> 'if' in skl_probe could be avoided had the function's structure been 
> better. 'if' in skl_remove is just fine, though.
> 
> Let's leave it as is.

it's also used in SOF:

sound/soc/sof/intel/hda.c:              intel_nhlt_free(nhlt);

that's why I suggested to factor the test so that both users don't need 
to add the if.