Re: [PATCHv5 04/20] PCI: mobiveil: Remove the flag MSI_FLAG_MULTI_PCI_MSI

[Marc Zyngier]

On 11/06/2019 17:59, Lorenzo Pieralisi wrote:
> On Fri, Apr 12, 2019 at 08:35:36AM +0000, Z.q. Hou wrote:
>> From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
>>
>> The current code does not support multiple MSIs, so remove
>> the corresponding flag from the msi_domain_info structure.
> 
> Please explain me what's the problem before removing multi MSI
> support.

The reason seems to be the following code in the allocator:

        WARN_ON(nr_irqs != 1);
        mutex_lock(&msi->lock);

        bit = find_first_zero_bit(msi->msi_irq_in_use, msi->num_of_vectors);
        if (bit >= msi->num_of_vectors) {
                mutex_unlock(&msi->lock);
                return -ENOSPC;
        }

        set_bit(bit, msi->msi_irq_in_use);

So instead of fixing the allocator, the author prefers disabling
the feature. I'm not sure whether that is an acceptable outcome...

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...