[PATCH] irqchip: let the probe of APLIC be earlier than IMSIC

[Anup Patel]

On Fri, Aug 2, 2024 at 1:27 PM Vincent Chen <vincent.chen at sifive.com> wrote:
>
> When the debug message of driver/base/dd.c is enabled, the following
> error messages are present in the boot log:
>
> [    0.207941] platform d000000.aplic: error -EPROBE_DEFER: supplier
> 28000000.imsics not ready
> [    0.208115] platform d000000.aplic: Added to deferred list

We are relying on fw_devlink implemented by Linux DD core to do the
probe ordering. The above prober defer message implies that the
Linux DD core is doing its job correctly.

>
> The reason for this error message is that the probe of APLIC is executed
> earlier than IMSIC. This error also causes all the platform devices
> connected to the APLIC to be added to the deferred list. Because both
> APLIC and IMSIC are registered by device_initcall, this patch adjusts the
> compile order of APLIC and IMSIC to ensure that the probe of IMSIC is
> executed earlier than the probe of APLIC.
>
> Signed-off-by: Vincent Chen <vincent.chen at sifive.com>
> ---
>  drivers/irqchip/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 15635812b2d6..3c09666569d6 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -96,9 +96,9 @@ obj-$(CONFIG_QCOM_MPM)                        += irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)              += irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)            += irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)               += irq-riscv-intc.o
> +obj-$(CONFIG_RISCV_IMSIC)              += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
>  obj-$(CONFIG_RISCV_APLIC)              += irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
>  obj-$(CONFIG_RISCV_APLIC_MSI)          += irq-riscv-aplic-msi.o
> -obj-$(CONFIG_RISCV_IMSIC)              += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o

First of all there is no issue here.

Secondly, changing compilation order in Makefile to influence
the probe order will not help in any way.

>  obj-$(CONFIG_SIFIVE_PLIC)              += irq-sifive-plic.o
>  obj-$(CONFIG_STARFIVE_JH8100_INTC)     += irq-starfive-jh8100-intc.o
>  obj-$(CONFIG_IMX_IRQSTEER)             += irq-imx-irqsteer.o
> --
> 2.34.1
>

Regards,
Anup