Re: [PATCH v2 3/3] mmc: mediatek: add support for SDIO eint irq

From: Axe Yang
Date: Mon Jan 17 2022 - 02:36:36 EST


Andy, patchset v3 is uploaded. I fixed most of the defect you pointed
out.
And in msdc_sdio_eint_irq(), you asked why do we need flags, the flags
is for spin lock irq save/restore, so I keep it.

On Tue, 2022-01-11 at 13:46 +0200, Andy Shevchenko wrote:
> On Tue, Jan 11, 2022 at 09:40:46AM +0800, Axe Yang wrote:
> > Add support for eint irq when MSDC is used as an SDIO host. This
>
> IRQ
>
> > feature requires SDIO device support async irq function. With this
>
> IRQ
>
> > feature,SDIO host can be awakened by SDIO card in suspend state,
>
> feature, SDIO
>
> > 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
>
> MSDC
>
> > to support SDIO eint irq. Pinctrls named state_dat1 and state_eint
>
> IRQ
>
> > 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;
> > ...
> > };
>
> ...
>
> > - * Copyright (c) 2014-2015 MediaTek Inc.
> > + * Copyright (c) 2014-2022 MediaTek Inc.
>
> Shouldn't it be rather like
>
> * Copyright (c) 2014-2015,2022 MediaTek Inc.
>
> ?
>
> ...
>
> > +static irqreturn_t msdc_sdio_eint_irq(int irq, void *dev_id)
> > +{
> > + unsigned long flags;
> > + struct msdc_host *host = (struct msdc_host *)dev_id;
>
> No casting is needed.
>
> > + struct mmc_host *mmc = mmc_from_priv(host);
>
> Perhaps reversed xmas tree order
>
> struct msdc_host *host = dev_id;
> struct mmc_host *mmc = mmc_from_priv(host);
> unsigned long flags;
>
> ?
>
> But hey, why do you need flags?

falgs is for spin lock irq save/restore.

>
> > + spin_lock_irqsave(&host->lock, flags);
> > + if (likely(host->sdio_irq_cnt > 0)) {
> > + disable_irq_nosync(host->eint_irq);
> > + disable_irq_wake(host->eint_irq);
> > + host->sdio_irq_cnt--;
> > + }
> > + spin_unlock_irqrestore(&host->lock, flags);
> > +
> > + sdio_signal_irq(mmc);
> > +
> > + return IRQ_HANDLED;
> > +}
>
> ...
>
> > +static int msdc_request_dat1_eint_irq(struct msdc_host *host)
> > +{
> > + struct gpio_desc *desc;
> > + int irq, ret;
> > +
> > + 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;
> > + ret = devm_request_threaded_irq(host->dev, irq, NULL,
> > msdc_sdio_eint_irq,
> > + IRQF_TRIGGER_LOW | IRQF_ONESHOT
> > | IRQF_NO_AUTOEN,
> > + "sdio-eint", host);
> > +
>
> Redundant blank line.
>
> > + if (!ret)
> > + host->eint_irq = irq;
> > +
> > + return ret;
>
> I guess I have already commented on this, i.e. use standard pattern
>
> if (ret)
> return ret;
>
> ...
> return 0;
>
> > +}
>
> ...
>
> > + host->pins_eint = pinctrl_lookup_state(host->pinctrl,
> > "state_eint");
> > + if (IS_ERR(host->pins_eint)) {
> > + dev_dbg(&pdev->dev, "Cannot find pinctrl
> > eint!\n");
>
> In debug mode of pin control this will bring a duplicate message.
>
> > + } else {
> > + host->pins_dat1 = pinctrl_lookup_state(host-
> > >pinctrl, "state_dat1");
> > + if (IS_ERR(host->pins_dat1)) {
> > + ret = dev_err_probe(&pdev->dev,
> > PTR_ERR(host->pins_dat1),
> > + "Cannot find
> > pinctrl dat1!\n");
> > + goto host_free;
> > + }
> > +
> > + host->sdio_eint_ready = true;
> > + }
> > + }
>
>