Hi James,
> > > May 26 07:44:33 xo-96-6d-f4 kernel: [ 198.341764] mmc0: Timeout waiting for hardware interrupt.
> > > May 26 07:44:33 xo-96-6d-f4 kernel: [ 198.341784] mwifiex_sdio mmc0:0001:1: read mp_regs failed
> >
> > I was expecting that mwifiex_sdio_resume handler is called before
> > the SDIO interrupt function is called.
>
> This does not happen. The SDIO interrupt function is always called
> before the mwifiex_sdio_resume handler.
I see.
>
> Method to test:
>
> --- a/drivers/net/wireless/mwifiex/sdio.c
> +++ b/drivers/net/wireless/mwifiex/sdio.c
> @@ -712,6 +712,9 @@ static void mwifiex_interrupt_status(struct mwifiex_adapter *adapter)
> u32 sdio_ireg;
> unsigned long flags;
>
> + if (adapter->is_suspended)
> + dev_warn(adapter->dev, "interrupt while adapter is suspended\n");
> +
> if (mwifiex_read_data_sync(adapter, card->mp_regs, MAX_MP_REGS,
> REG_PORT | MWIFIEX_SDIO_BYTE_MODE_MASK,
> 0)) {
>
> # grep -c "after resume" /var/log/messages
> 630
> # grep -c "interrupt while adapter" /var/log/messages
> 630
>
> Also, sometimes mwifiex_sdio_suspend runs while an SDIO register
> operation is in progress, because of an interrupt. I can reduce the
> frequency of the "mmc0: Timeout..." if I delay suspend until the
> register option is completed.
>
> This occurs roughly 3 out of 630 suspends.
>
> The platform is not SMP, even though it is mmp3. So I made an
> unpleasant hack:
>
> --- a/drivers/net/wireless/mwifiex/sdio.c
> +++ b/drivers/net/wireless/mwifiex/sdio.c
> @@ -54,6 +54,8 @@ static DEFINE_RATELIMIT_STATE(noskb_rs,
> 120 * HZ,
> 1);
>
> +volatile static bool in_progress;
> +
> /*
> * SDIO probe.
> *
> @@ -206,6 +208,22 @@ static int mwifiex_sdio_suspend(struct device *dev)
> struct mwifiex_adapter *adapter;
> mmc_pm_flag_t pm_flag = 0;
> int ret = 0;
> + int i;
> +
> + /* an attempt to avoid suspend for a short time while sdio i/o is in progress */
> + if (in_progress) {
> + pr_err("suspend: sdio i/o is in_progress, delaying\n");
> + WARN_ON_ONCE(1);
> +
> + i = 50;
> + while (in_progress && i-- > 0) msleep(10);
> +
> + if (in_progress) {
> + pr_err("suspend: sdio i/o was in_progress\n");
> + WARN_ON_ONCE(1);
> + return -EFAULT;
> + }
> + }
I think MMC has better knowledge about the host being claimed or not. If a register read/write is in progress, host->claimed and host->claim_cnt should have non-zero values.
So, the delay logic is better to be done in MMC before calling driver's suspend handler.
Regards,
Bing
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