Re: [PATCH hyperv-next v5 08/11] Drivers: hv: vmbus: Get the IRQ number from DeviceTree

[Rob Herring]

On Fri, Mar 7, 2025 at 4:03 PM Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx> wrote:
>
> The VMBus driver uses ACPI for interrupt assignment on
> arm64 hence it won't function in the VTL mode where only
> DeviceTree can be used.
>
> Update the VMBus driver to discover interrupt configuration
> from DT.
>
> Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
> ---
>  drivers/hv/vmbus_drv.c | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index 75eb1390b45c..c8474b48dcd2 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -2345,6 +2345,36 @@ static int vmbus_acpi_add(struct platform_device *pdev)
>  }
>  #endif
>
> +static int __maybe_unused vmbus_set_irq(struct platform_device *pdev)
> +{
> +       struct irq_data *data;
> +       int irq;
> +       irq_hw_number_t hwirq;
> +
> +       irq = platform_get_irq(pdev, 0);
> +       if (irq == 0) {
> +               pr_err("VMBus interrupt mapping failure\n");
> +               return -EINVAL;
> +       }
> +       if (irq < 0) {
> +               pr_err("VMBus interrupt data can't be read from DeviceTree, error %d\n", irq);
> +               return irq;
> +       }

I don't think why you couldn't get the interrupt is important. Just
check for (irq <= 0) and be done with it. I'm not even sure if
returning 0 is possible now. There's a long history to that and
NO_IRQ.

Rob