RE: [patch 06/20] genirq/msi: Check for invalid MSI parent domain usage

[Thomas Gleixner]

On Fri, Nov 18 2022 at 07:50, Kevin Tian wrote:
>> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> Sent: Friday, November 11, 2022 9:57 PM
>> 
>> @@ -937,13 +937,21 @@ int msi_domain_alloc_irqs_descs_locked(s
>> 
>>  	lockdep_assert_held(&dev->msi.data->mutex);
>> 
>> +	if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain))) {
>> +		ret = -EINVAL;
>> +		goto free;
>> +	}
>> +
>> +	/* Frees allocated descriptors in case of failure. */
>>  	ret = msi_domain_add_simple_msi_descs(info, dev, nvec);
>>  	if (ret)
>>  		return ret;
>
> it's unusual to see a direct return when error unwind is already required
> at an early failure point. is it something which can be improved here?

It's redundant in this case, but you are right it looks weird.