Re: [PATCH 3/3] amba: Properly handle device probe without IRQ domain

[Rob Herring <robh+dt@kernel.org>]

+Saravana

Saravana mentioned to me there may be some issues with this one...


On Mon, Aug 16, 2021 at 2:43 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>
> of_amba_device_create() uses irq_of_parse_and_map() to translate
> a DT interrupt specification into a Linux virtual interrupt number.
>
> But it doesn't properly handle the case where the interrupt controller
> is not yet available, eg, when pl011 interrupt is connected to MBIGEN
> interrupt controller, because the mbigen initialization is too late,
> which will lead to no IRQ due to no IRQ domain found, log is shown below,
>   "irq: no irq domain found for uart0 !"
>
> use of_irq_get() to return -EPROBE_DEFER as above, and in the function
> amba_device_try_add()/amba_device_add(), it will properly handle in such
> case, also return 0 in other fail cases to be consistent as before.
>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Reported-by: Ruizhe Lin <linruizhe@huawei.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>  drivers/amba/bus.c    | 27 +++++++++++++++++++++++++++
>  drivers/of/platform.c |  6 +-----
>  2 files changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
> index 36f2f42c8014..720aa6cdd402 100644
> --- a/drivers/amba/bus.c
> +++ b/drivers/amba/bus.c
> @@ -19,6 +19,7 @@
>  #include <linux/clk/clk-conf.h>
>  #include <linux/platform_device.h>
>  #include <linux/reset.h>
> +#include <linux/of_irq.h>
>
>  #include <asm/irq.h>
>
> @@ -371,12 +372,38 @@ static void amba_device_release(struct device *dev)
>         kfree(d);
>  }
>
> +static int of_amba_device_decode_irq(struct amba_device *dev)
> +{
> +       struct device_node *node = dev->dev.of_node;
> +       int i, irq = 0;
> +
> +       if (IS_ENABLED(CONFIG_OF_IRQ) && node) {
> +               /* Decode the IRQs and address ranges */
> +               for (i = 0; i < AMBA_NR_IRQS; i++) {
> +                       irq = of_irq_get(node, i);
> +                       if (irq < 0) {
> +                               if (irq == -EPROBE_DEFER)
> +                                       return irq;
> +                               irq = 0;
> +                       }
> +
> +                       dev->irq[i] = irq;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
>  static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
>  {
>         u32 size;
>         void __iomem *tmp;
>         int i, ret;
>
> +       ret = of_amba_device_decode_irq(dev);
> +       if (ret)
> +               goto err_out;
> +
>         ret = request_resource(parent, &dev->res);
>         if (ret)
>                 goto err_out;
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 74afbb7a4f5e..32d5ff8df747 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -222,7 +222,7 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
>  {
>         struct amba_device *dev;
>         const void *prop;
> -       int i, ret;
> +       int ret;
>
>         pr_debug("Creating amba device %pOF\n", node);
>
> @@ -253,10 +253,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
>         if (prop)
>                 dev->periphid = of_read_ulong(prop, 1);
>
> -       /* Decode the IRQs and address ranges */
> -       for (i = 0; i < AMBA_NR_IRQS; i++)
> -               dev->irq[i] = irq_of_parse_and_map(node, i);
> -
>         ret = of_address_to_resource(node, 0, &dev->res);
>         if (ret) {
>                 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
> --
> 2.26.2
>