linux-kernel - Re: [PATCH v4 3/3] mmc: mediatek: add support for SDIO eint IRQ

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Date:   Wed, 19 Jan 2022 21:47:56 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Axe Yang <axe.yang@...iatek.com>
Cc:     Ulf Hansson <ulf.hansson@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Chaotian Jing <chaotian.jing@...iatek.com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
        Satya Tangirala <satyat@...gle.com>,
        Wolfram Sang <wsa+renesas@...g-engineering.com>,
        Lucas Stach <dev@...xeye.de>,
        Eric Biggers <ebiggers@...gle.com>,
        Andrew Jeffery <andrew@...id.au>,
        Stephen Boyd <swboyd@...omium.org>,
        Kiwoong Kim <kwmad.kim@...sung.com>,
        Yue Hu <huyue2@...ong.com>, Tian Tao <tiantao6@...ilicon.com>,
        angelogioacchino.delregno@...labora.com, linux-mmc@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org,
        Yong Mao <yong.mao@...iatek.com>
Subject: Re: [PATCH v4 3/3] mmc: mediatek: add support for SDIO eint IRQ

On Wed, Jan 19, 2022 at 06:32:12PM +0800, Axe Yang wrote:
> Add support for eint IRQ when MSDC is used as an SDIO host. This
> feature requires SDIO device support async IRQ function. With this
> feature, SDIO host can be awakened by SDIO card in suspend state,
> without additional pin.
> 
> MSDC driver will time-share the SDIO DAT1 pin. During suspend, MSDC
> turn off clock and switch SDIO DAT1 pin to GPIO mode. And during
> resume, switch GPIO function back to DAT1 mode then turn on clock.
> 
> Some device tree property should be added or modified in MSDC node
> to support SDIO eint IRQ. Pinctrls named state_dat1 and state_eint
> are mandatory. And cap-sdio-async-irq flag is necessary since this
> feature depends on asynchronous interrupt:
>         &mmcX {
>                 ...
>                 pinctrl-names = "default", "state_uhs", "state_eint",
>                                 "state_dat1";
>                 ...
>                 pinctrl-2 = <&mmc2_pins_eint>;
>                 pinctrl-3 = <&mmc2_pins_dat1>;
>                 ...
>                 cap-sdio-async-irq;
>                 ...
>         };
> 
> Signed-off-by: Axe Yang <axe.yang@...iatek.com>

The submitters SoB must be last among all SoB tags. Please, read Submitting
Patches document carefully.

> Signed-off-by: Yong Mao <yong.mao@...iatek.com>

Who is they, why their SoB appeared here?

...

>  /*
> - * Copyright (c) 2014-2015 MediaTek Inc.
> + * Copyright (c) 2022 MediaTek Inc.

This doesn't feel right. Why did you remove old years?

>   * Author: Chaotian.Jing <chaotian.jing@...iatek.com>
>   */

...

> +	desc = devm_gpiod_get(host->dev, "eint", GPIOD_IN);
> +	if (IS_ERR(desc))
> +		return PTR_ERR(desc);

> +	ret = gpiod_to_irq(desc);
> +	if (ret < 0)
> +		return ret;
> +
> +	irq = ret;

Since both of them are local variables and there is no specific use of the
returned value, I believe it's fine just to

	irq = gpiod_to_irq(desc);
	...

Hmm... I was wondering if you can use fwnode_irq_get_byname().
Ah, it's not (yet) in upstream.

...

>  static int __maybe_unused msdc_runtime_suspend(struct device *dev)
>  {
> +	unsigned long flags;

Can you keep reversed xmas tree order?

>  	struct mmc_host *mmc = dev_get_drvdata(dev);
>  	struct msdc_host *host = mmc_priv(mmc);

(it means to add new variable here)

>  	return 0;
>  }

...

>  static int __maybe_unused msdc_runtime_resume(struct device *dev)
>  {
> +	unsigned long flags;

Ditto.

>  	struct mmc_host *mmc = dev_get_drvdata(dev);
>  	struct msdc_host *host = mmc_priv(mmc);
>  	int ret;

>  	return 0;
>  }

-- 
With Best Regards,
Andy Shevchenko