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References: <20211217001238.16298-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
In-Reply-To: <20211217001238.16298-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
From:   Rob Herring <robh+dt@kernel.org>
Date:   Thu, 16 Dec 2021 18:39:13 -0600
Message-ID: <CAL_JsqLf0FHYt-+4hEG3FkecrBJOwd=ub_yeEKWZ1DKPUycgkQ@mail.gmail.com>
Subject: Re: [PATCH] ata: pata_of_platform: Use of_irq_to_resource() to
 populate IRQ resource
To:     Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Cc:     Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        "open list:LIBATA SUBSYSTEM (Serial and Parallel ATA drivers)" 
        <linux-ide@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Prabhakar <prabhakar.csengg@gmail.com>
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On Thu, Dec 16, 2021 at 6:12 PM Lad Prabhakar
<prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
>
> platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> allocation of IRQ resources in DT core code, this causes an issue
> when using hierarchical interrupt domains using "interrupts" property
> in the node as this bypassed the hierarchical setup and messed up the
> irq chaining.
>
> In preparation for removal of static setup of IRQ resource from DT core
> code use of_irq_to_resource().
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> Hi,
>
> Dropping usage of platform_get_resource() was agreed based on
> the discussion [0].
>
> [0] https://patchwork.kernel.org/project/linux-renesas-soc/
> patch/20211209001056.29774-1-prabhakar.mahadev-lad.rj@bp.renesas.com/
>
> Cheers,
> Prabhakar
> ---
>  drivers/ata/pata_of_platform.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c
> index 35aa158fc976..557f349eb533 100644
> --- a/drivers/ata/pata_of_platform.c
> +++ b/drivers/ata/pata_of_platform.c
> @@ -9,6 +9,7 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/of_address.h>
> +#include <linux/of_irq.h>
>  #include <linux/platform_device.h>
>  #include <linux/ata_platform.h>
>  #include <linux/libata.h>
> @@ -25,11 +26,12 @@ static int pata_of_platform_probe(struct platform_device *ofdev)
>         struct device_node *dn = ofdev->dev.of_node;
>         struct resource io_res;
>         struct resource ctl_res;
> -       struct resource *irq_res;
> +       struct resource irq_res;
>         unsigned int reg_shift = 0;
>         int pio_mode = 0;
>         int pio_mask;
>         bool use16bit;
> +       int irq;
>
>         ret = of_address_to_resource(dn, 0, &io_res);
>         if (ret) {
> @@ -45,7 +47,9 @@ static int pata_of_platform_probe(struct platform_device *ofdev)
>                 return -EINVAL;
>         }
>
> -       irq_res = platform_get_resource(ofdev, IORESOURCE_IRQ, 0);
> +       irq = of_irq_to_resource(dn, 0, &irq_res);

No, platform_get_irq() please. I really want to get rid of the 4 users
of of_irq_to_resource() in the tree, not add more.

Yeah, that means __pata_platform_probe() needs to change, but it's all
of 2 callers. Really, I think pata_platform.c and pata_of_platform.c
should be merged. I'm guessing the separation traces back to DT using
a different bus type.

Rob