Re: [PATCH v2 3/3] misc: pci_endpoint_test: Fix irq_type to convey the correct type

[Kunihiko Hayashi <hayashi.kunihiko@socionext.com>]

Hi Manivannan,

On 2025/01/28 23:32, Manivannan Sadhasivam wrote:
> On Wed, Jan 22, 2025 at 11:24:46AM +0900, Kunihiko Hayashi wrote:
>> There are two variables that indicate the interrupt type to be used
>> in the next test execution, "irq_type" as global and test->irq_type.
>>
>> The global is referenced from pci_endpoint_test_get_irq() to preserve
>> the current type for ioctl(PCITEST_GET_IRQTYPE).
>>
>> The type set in this function isn't reflected in the global "irq_type",
>> so ioctl(PCITEST_GET_IRQTYPE) returns the previous type.
>> As a result, the wrong type will be displayed in "pcitest" as follows:
>>
>>      # pcitest -i 0
>>      SET IRQ TYPE TO LEGACY:         OKAY
>>      # pcitest -I
>>      GET IRQ TYPE:           MSI
>>
>> Fix this issue by propagating the current type to the global "irq_type".
>>
> 
> This is becoming a nuisance. I think we should get rid of the global 'irq_type'
> and just stick to the one that is configurable using IOCTL command. Even if the
> user has configured the global 'irq_type' it is bound to change with IOCTL
> command.

We can add a new member of 'struct pci_endpoint_test' instead of the global
'irq_type'.

If I remove the global 'irq_type', the following module parameter description
will also be removed.

>> module_param(irq_type, int, 0444);
>> MODULE_PARM_DESC(irq_type, "IRQ mode selection in pci_endpoint_test (0 - Legacy, 1 - MSI, 2 - MSI-X)");

I'm concerned about compatibility. Is there any problem with removing this?

Thank you,

---
Best Regards
Kunihiko Hayashi