Re: [PATCH] mmc: sdhci: add spin lock for sdhci_set_default_irqs in sdhci_init

[Adrian Hunter <adrian.hunter@intel.com>]

On 15/04/20 12:00 pm, haibo.chen@nxp.com wrote:
> From: Haibo Chen <haibo.chen@nxp.com>
> 
> When use one SDIO wifi which enable the runtime PM feature on i.MX6SX,
> we meet system hang. This hang happened during the usdhc runtime resume,
> in sdhci_init(), when call the sdhci_set_default_irqs. One interrupt
> (SDHCI_INT_CARD_INT) triggered just after the host->ier update and before
> the write of register SDHCI_SIGNAL_ENABLE. So in sdhci_irq, it will skip
> the call of sdio_signal_irq() because current host->ier do not set the
> SDHCI_INT_CARD_INT. So this SDIO wifi interrupt always keep triggered,
> let the system stuck in irq handle, can't response any other thread.
> 
> This patch add spin lock for the sdhci_set_default_irqs to fix this issue.
> 
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 3f716466fcfd..79b6324a500c 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -317,6 +317,7 @@ static void sdhci_config_dma(struct sdhci_host *host)
>  static void sdhci_init(struct sdhci_host *host, int soft)
>  {
>  	struct mmc_host *mmc = host->mmc;
> +	unsigned long flags;
>  
>  	if (soft)
>  		sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> @@ -326,7 +327,9 @@ static void sdhci_init(struct sdhci_host *host, int soft)
>  	if (host->v4_mode)
>  		sdhci_do_enable_v4_mode(host);
>  
> +	spin_lock_irqsave(&host->lock, flags);
>  	sdhci_set_default_irqs(host);
> +	spin_unlock_irqrestore(&host->lock, flags);
>  
>  	host->cqe_on = false;
>  
>