Re: [PATCH 2/2] mmc: sdhci: provide isr for card-detect interrupts

From: Adrian Hunter
Date: Tue Apr 11 2017 - 06:38:14 EST


On 11/04/17 13:20, Jisheng Zhang wrote:
> We found one issue on BG4CT platforms with GPIO for sdcar card detect
> interrupt: remove sdcard when there's read write access to the sdcard,
> sometimes the card remove event can't be handled for a long time, so
> the system still think the sdcard is still plugged in. It turns out
> that the sdhci_card_event() is missing in common slot gpio's card
> detect isr.

->card_event() is called by mmc_rescan(). Why is that too late?

>
> We fix this issue by providing sdhci's own isr for card-detect
> interrupts. In this own isr, we call sdhci_card_event() then process
> the change of state.

Why doesn't every other host controller have this problem?

>
> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 63bc33a54d0d..b6c5021a5892 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2777,6 +2777,16 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
> return result;
> }
>
> +static irqreturn_t sdhci_cd_irq(int irq, void *dev_id)
> +{
> + struct mmc_host *mmc = dev_id;
> + struct sdhci_host *host = mmc_priv(mmc);
> +
> + mmc->ops->card_event(mmc);
> + mmc_detect_change(host->mmc, msecs_to_jiffies(200));
> + return IRQ_HANDLED;
> +}
> +
> static irqreturn_t sdhci_thread_irq(int irq, void *dev_id)
> {
> struct sdhci_host *host = dev_id;
> @@ -3617,6 +3627,8 @@ int __sdhci_add_host(struct sdhci_host *host)
>
> sdhci_init(host, 0);
>
> + mmc_gpio_set_cd_isr(mmc, sdhci_cd_irq);
> +
> ret = request_threaded_irq(host->irq, sdhci_irq, sdhci_thread_irq,
> IRQF_SHARED, mmc_hostname(mmc), host);
> if (ret) {
>