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

Rob Herring
2025-03-13T18:44:54Z

On Fri, Mar 7, 2025 at 4:03 PM Roman Kisel <romank@linux.microsoft.com> 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@linux.microsoft.com>
> Reviewed-by: Michael Kelley <mhklinux@outlook.com>
> ---
> 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