Re: [patch 07/32] genirq/msi: Count the allocated MSI descriptors

From: Thomas Gleixner
Date: Sat Nov 27 2021 - 14:25:03 EST


On Sat, Nov 27 2021 at 13:19, Greg Kroah-Hartman wrote:
> On Sat, Nov 27, 2021 at 02:22:38AM +0100, Thomas Gleixner wrote:
>> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>
> No changelog?

Bah. This one should not be there at all.

> Anyway, why do we care about the number of decriptors?
>> +/**
>> + * msi_device_num_descs - Query the number of allocated MSI descriptors of a device
>> + * @dev: The device to read from
>> + *
>> + * Note: This is a lockless snapshot of msi_device_data::num_descs
>> + *
>> + * Returns the number of MSI descriptors which are allocated for @dev
>> + */
>> +unsigned int msi_device_num_descs(struct device *dev)
>> +{
>> + if (dev->msi.data)
>> + return dev->msi.data->num_descs;
>
> As this number can change after it is read, what will callers do with
> it?

I wanted to get rid of this, but then forgot. Getting old.

Thanks,

tglx