Re: [PATCH v3 1/8] driver core: bus: add irq_get_affinity callback to bus_type

[John Garry <john.g.garry@oracle.com>]

On 13/11/2024 13:54, Greg Kroah-Hartman wrote:
>> diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
>> b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
>> index 342d75f12051..5172af77a3f0 100644
>> --- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
>> +++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
>> @@ -3636,6 +3636,7 @@ static struct platform_driver hisi_sas_v2_driver = {
>>                 .name = DRV_NAME,
>>                 .of_match_table = sas_v2_of_match,
>>                 .acpi_match_table = ACPI_PTR(sas_v2_acpi_match),
>> +               .irq_get_affinity_mask = hisi_sas_v2_get_affinity_mask,
>>         },
>> };
>>
>>
>>> If no one objects, I go ahead and add the callback to struct
>>> device_driver.
>> I'd wait for Christoph and Greg to both agree. I was just wondering why we
>> use bus_type.
> bus types are good to set it at a bus level so you don't have to
> explicitly set it at each-and-every-driver.  Depends on what you want
> this to be, if it is a "all drivers of this bus type will have the same
> callback" then put it on the bus.  otherwise if you are going to
> mix/match on a same bus, then put it in the driver structure.

Understood, I think all drivers on same bus will use the same callback.

FWIW, most drivers of interest are pci drivers, so I thought that it 
would simply be a change like this (for those drivers if we use struct 
device_driver):

@@ -1442,6 +1455,7 @@ int __pci_register_driver(struct pci_driver
*drv, struct module *owner,
        drv->driver.mod_name = mod_name;
        drv->driver.groups = drv->groups;
        drv->driver.dev_groups = drv->dev_groups;
+       drv->driver.irq_get_affinity = pci_device_irq_get_affinity;

Thanks,
John