> -----Original Message-----
> From: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> Sent: 2020年5月26日 19:43
> To: BOUGH CHEN <haibo.chen@xxxxxxx>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>; linux-mmc@xxxxxxxxxxxxxxx;
> dl-linux-imx <linux-imx@xxxxxxx>; Shawn Guo <shawnguo@xxxxxxxxxx>;
> Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>; Sascha Hauer
> <kernel@xxxxxxxxxxxxxx>; Fabio Estevam <festevam@xxxxxxxxx>; Linux PM
> <linux-pm@xxxxxxxxxxxxxxx>; Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
> Subject: Re: [PATCH] mmc: host: sdhci-esdhc-imx: add wakeup feature for GPIO
> CD pin
>
> + Rafael, linux-pm
>
> On Tue, 26 May 2020 at 10:41, <haibo.chen@xxxxxxx> wrote:
> >
> > From: Haibo Chen <haibo.chen@xxxxxxx>
> >
> > When use the specific GPIO to detect the card insert/remove, we can
> > also add the GPIO as a wakeup source. When system suspend, insert or
> > remove the card can wakeup the system.
>
> Yes, this makes perfect sense! However...
>
> >
> > Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
> > ---
> > drivers/mmc/host/sdhci-esdhc-imx.c | 19 +++++++++++++++++--
> > 1 file changed, 17 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c
> > b/drivers/mmc/host/sdhci-esdhc-imx.c
> > index 5398af4824c3..7af9d87d4245 100644
> > --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> > @@ -1599,6 +1599,11 @@ static int sdhci_esdhc_imx_probe(struct
> platform_device *pdev)
> > if (esdhc_is_usdhc(imx_data)) {
> > host->quirks2 |=
> SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
> > host->mmc->caps |= MMC_CAP_1_8V_DDR |
> > MMC_CAP_3_3V_DDR;
> > +
> > + /* GPIO CD can be set as a wakeup source */
> > + host->mmc->caps |= MMC_CAP_CD_WAKE;
> > + device_init_wakeup(&pdev->dev, true);
> > +
>
> ... if the device is attached to a genpd (a PM domain), this may cause it to stay
> powered on in the system suspend state. Not sure if that can cause a problem
> for you? Wasting energy?
>
> In any case, I think it's wrong to make "&pdev->dev" wakeup capable, like this.
> Especially as at it's the GPIO controller that manages the system wakeup irq.
Yes, that's reasonable.
>
> > if (!(imx_data->socdata->flags & ESDHC_FLAG_HS200))
> > host->quirks2 |=
> SDHCI_QUIRK2_BROKEN_HS200;
> >
> > @@ -1734,8 +1739,15 @@ static int sdhci_esdhc_suspend(struct device
> *dev)
> > mmc_retune_needed(host->mmc);
> >
> > ret = sdhci_suspend_host(host);
> > - if (!ret)
> > - return pinctrl_pm_select_sleep_state(dev);
> > + if (ret)
> > + return ret;
> > +
> > + ret = pinctrl_pm_select_sleep_state(dev);
> > + if (ret)
> > + return ret;
> > +
> > + if (device_may_wakeup(dev))
> > + ret = mmc_gpio_set_cd_wake(host->mmc, true);
>
> With the above said, I think the best available approach at this point, is to just
> call mmc_gpio_set_cd_wake() - and just skip checking device_may_wakeup().
>
> BTW, mmc_gpio_set_cd_wake() calls enable_irq_wake(), which doesn't require
> the "dev" to be wakeup capable. So this is fine!
>
> Yes, it means that the IRQ will be configured as a system wakeup, without
> letting user space to have a say about it. I guess we can live with that
> limitation.
>
Okay, I will send a v2 patch according to your suggestion.
Thanks!
Haibo Chen
> >
> > return ret;
> > }
> > @@ -1759,6 +1771,9 @@ static int sdhci_esdhc_resume(struct device *dev)
> > if (host->mmc->caps2 & MMC_CAP2_CQE)
> > ret = cqhci_resume(host->mmc);
> >
> > + if (!ret && device_may_wakeup(dev))
> > + ret = mmc_gpio_set_cd_wake(host->mmc, false);
> > +
> > return ret;
> > }
> > #endif
> > --
> > 2.17.1
> >
>
> Kind regards
> Uffe
