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    SubjectRe: [RFC PATCH] of: platform: Skip mapping of interrupts in of_device_alloc()
    Hi Rob,

    Thank you for the review.

    On Thu, Dec 9, 2021 at 3:08 AM Rob Herring <robh+dt@kernel.org> wrote:
    >
    > On Wed, Dec 8, 2021 at 6:11 PM Lad Prabhakar
    > <prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
    > >
    > > of_device_alloc() in early boot stage creates a interrupt mapping if
    > > there exists a "interrupts" property in the node.
    > >
    > > For hierarchical interrupt domains using "interrupts" property in the node
    > > bypassed the hierarchical setup and messed up the irq setup.
    > >
    > > This patch adds a check in of_device_alloc() to skip interrupt mapping if
    > > "not-interrupt-producer" property is present in the node. This allows
    > > nodes to describe the interrupts using "interrupts" property.
    > >
    > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
    > > ---
    > > Hi All,
    > >
    > > Spawning from discussion [1], here is simple patch (not the ideal probably
    > > welcome for suggestions) from stopping the OF code from creating a map for
    > > the interrupts when using "interrupts" property.
    > >
    > > [1] https://lore.kernel.org/lkml/87pmqrck2m.wl-maz@kernel.org/
    > > T/#mbd1e47c1981082aded4b32a52e2c04291e515508
    > >
    > > Cheers,
    > > Prabhakar
    > > ---
    > > drivers/of/platform.c | 13 ++++++++++---
    > > 1 file changed, 10 insertions(+), 3 deletions(-)
    > >
    > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c
    > > index b3faf89744aa..629776ca1721 100644
    > > --- a/drivers/of/platform.c
    > > +++ b/drivers/of/platform.c
    > > @@ -114,7 +114,7 @@ struct platform_device *of_device_alloc(struct device_node *np,
    > > struct device *parent)
    > > {
    > > struct platform_device *dev;
    > > - int rc, i, num_reg = 0, num_irq;
    > > + int rc, i, num_reg = 0, num_irq = 0;
    > > struct resource *res, temp_res;
    > >
    > > dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
    > > @@ -124,7 +124,14 @@ struct platform_device *of_device_alloc(struct device_node *np,
    > > /* count the io and irq resources */
    > > while (of_address_to_resource(np, num_reg, &temp_res) == 0)
    > > num_reg++;
    > > - num_irq = of_irq_count(np);
    > > +
    > > + /*
    > > + * we don't want to map the interrupts of hierarchical interrupt domain
    > > + * into the parent domain yet. This will be the job of the hierarchical
    > > + * interrupt driver code to map the interrupts as and when needed.
    > > + */
    > > + if (!of_property_read_bool(np, "not-interrupt-producer"))
    > > + num_irq = of_irq_count(np);
    >
    > The property won't fly for sure. A compatible match table could work
    > here, but I don't really want another temporary solution.
    >
    Agreed.

    > > /* Populate the resource table */
    > > if (num_irq || num_reg) {
    > > @@ -140,7 +147,7 @@ struct platform_device *of_device_alloc(struct device_node *np,
    > > rc = of_address_to_resource(np, i, res);
    > > WARN_ON(rc);
    > > }
    > > - if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
    > > + if (num_irq && of_irq_to_resource_table(np, res, num_irq) != num_irq)
    >
    > You might want to look at commit 9ec36cafe43b ("of/irq: do irq
    > resolution in platform_get_irq"). The intent was to remove this code,
    > but looks like the cleanup has a ways to go 7 years on. Primarily,
    > it's convert any platform_get_resource(pdev, IORESOURCE_IRQ, n) call
    > to platform_get_irq(). There's ~169 of those.
    >
    That's a good point converting all the drivers to use
    platform_get_irq() so that the resource allocation happens on demand,
    and the above code can be dropped.

    > There are probably some open coded accesses to pdev->resources too,
    > but I didn't spot any.
    >
    I'll have a closer look.

    Cheers,
    Prabhakar

    > Rob

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