Re: [PATCH v3 2/4] irqchip/qcom-pdc: Switch to using IRQCHIP_PLATFORM_DRIVER helper macros

From: John Stultz <john.stultz@linaro.org>
To: Saravana Kannan <saravanak@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Jason Cooper <jason@lakedaemon.net>,
	Marc Zyngier <maz@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Android Kernel Team <kernel-team@android.com>,
	lkml <linux-kernel@vger.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	linux-mediatek@lists.infradead.org,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	Hanks Chen <hanks.chen@mediatek.com>,
	CC Hwang <cc.hwang@mediatek.com>,
	Loda Chou <loda.chou@mediatek.com>
Subject: Re: [PATCH v3 2/4] irqchip/qcom-pdc: Switch to using IRQCHIP_PLATFORM_DRIVER helper macros
Date: Wed, 5 Aug 2020 00:44:21 -0700	[thread overview]
Message-ID: <CALAqxLVZ+rFE+hM9OtQ46NqpTHeLu6oKLNWKstLv1U5zbwyq7g@mail.gmail.com> (raw)
In-Reply-To: <20200718000637.3632841-3-saravanak@google.com>

On Fri, Jul 17, 2020 at 5:06 PM Saravana Kannan <saravanak@google.com> wrote:
>
> Switch the driver to use the helper macros. In addition to reducing the
> number of lines, this also adds module unload protection (if the driver
> is compiled as a module) by switching from module_platform_driver to
> builtin_platform_driver.
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>  drivers/irqchip/qcom-pdc.c | 26 +++-----------------------
>  1 file changed, 3 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c
> index 5b624e3295e4..c1c5dfad57cc 100644
> --- a/drivers/irqchip/qcom-pdc.c
> +++ b/drivers/irqchip/qcom-pdc.c
> @@ -432,28 +432,8 @@ static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
>         return ret;
>  }
>
> -static int qcom_pdc_probe(struct platform_device *pdev)
> -{
> -       struct device_node *np = pdev->dev.of_node;
> -       struct device_node *parent = of_irq_find_parent(np);
> -
> -       return qcom_pdc_init(np, parent);
> -}
> -
> -static const struct of_device_id qcom_pdc_match_table[] = {
> -       { .compatible = "qcom,pdc" },
> -       {}
> -};
> -MODULE_DEVICE_TABLE(of, qcom_pdc_match_table);
> -
> -static struct platform_driver qcom_pdc_driver = {
> -       .probe = qcom_pdc_probe,
> -       .driver = {
> -               .name = "qcom-pdc",
> -               .of_match_table = qcom_pdc_match_table,
> -               .suppress_bind_attrs = true,
> -       },
> -};
> -module_platform_driver(qcom_pdc_driver);
> +IRQCHIP_PLATFORM_DRIVER_BEGIN(qcom_pdc)
> +IRQCHIP_MATCH("qcom,pdc", qcom_pdc_init)
> +IRQCHIP_PLATFORM_DRIVER_END(qcom_pdc)
>  MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Power Domain Controller");
>  MODULE_LICENSE("GPL v2");

<sigh>
So this is where I bashfully admit I didn't get a chance to try this
patch series out, as I had success with a much older version of
Saravana's macro magic.

But unfortunately, now that this has landed in mainline, I'm seeing
boot regressions on db845c. :( This is in the non-modular case,
building the driver in.

I managed to bisect it down to this patch, and reverting it avoids the
issue. I don't see what is wrong right off, but I really need to get
to bed, so I'll dig further tomorrow.

Saravana: Apologies for not getting around to testing this beforehand!

thanks
-john