lkml.org 
[lkml]   [2021]   [Dec]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC PATCH] of: platform: Skip mapping of interrupts in of_device_alloc()
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.

> /* 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.

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

Rob

\
 
 \ /
  Last update: 2021-12-09 04:08    [W:0.116 / U:0.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site