Commit 89f3c365 authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
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mmc: sdhci: Fix SDIO IRQ thread deadlock 



Since commit c07a48c2 ("mmc: sdhci: Remove finish_tasklet"), the IRQ
thread might be used to complete requests, but the IRQ thread is also used
to process SDIO card interrupts. This can cause a deadlock when the SDIO
processing tries to access the card since that would also require the IRQ
thread. Change SDHCI to use sdio_signal_irq() to schedule a work item
instead. That also requires implementing the ->ack_sdio_irq() mmc host op.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Fixes: c07a48c2 ("mmc: sdhci: Remove finish_tasklet")
Reported-by: default avatarBrian Masney <masneyb@onstation.org>
Tested-by: default avatarBrian Masney <masneyb@onstation.org>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent c2c1e63a

drivers/mmc/host/sdhci.c

+13 −11
Original line number Diff line number Diff line
@@ -2137,6 +2137,17 @@ void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable) 
}

EXPORT_SYMBOL_GPL(sdhci_enable_sdio_irq);



static void sdhci_ack_sdio_irq(struct mmc_host *mmc)

{

	struct sdhci_host *host = mmc_priv(mmc);

	unsigned long flags;



	spin_lock_irqsave(&host->lock, flags);

	if (host->flags & SDHCI_SDIO_IRQ_ENABLED)

		sdhci_enable_sdio_irq_nolock(host, true);

	spin_unlock_irqrestore(&host->lock, flags);

}



int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,

				      struct mmc_ios *ios)

{
@@ -2585,6 +2596,7 @@ static const struct mmc_host_ops sdhci_ops = { 
	.get_ro		= sdhci_get_ro,

	.hw_reset	= sdhci_hw_reset,

	.enable_sdio_irq = sdhci_enable_sdio_irq,

	.ack_sdio_irq    = sdhci_ack_sdio_irq,

	.start_signal_voltage_switch	= sdhci_start_signal_voltage_switch,

	.prepare_hs400_tuning		= sdhci_prepare_hs400_tuning,

	.execute_tuning			= sdhci_execute_tuning,
@@ -3087,8 +3099,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id) 
		if ((intmask & SDHCI_INT_CARD_INT) &&

		    (host->ier & SDHCI_INT_CARD_INT)) {

			sdhci_enable_sdio_irq_nolock(host, false);

			host->thread_isr |= SDHCI_INT_CARD_INT;

			result = IRQ_WAKE_THREAD;

			sdio_signal_irq(host->mmc);

		}



		intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE |
@@ -3160,15 +3171,6 @@ static irqreturn_t sdhci_thread_irq(int irq, void *dev_id) 
		mmc_detect_change(mmc, msecs_to_jiffies(200));

	}



	if (isr & SDHCI_INT_CARD_INT) {

		sdio_run_irqs(host->mmc);



		spin_lock_irqsave(&host->lock, flags);

		if (host->flags & SDHCI_SDIO_IRQ_ENABLED)

			sdhci_enable_sdio_irq_nolock(host, true);

		spin_unlock_irqrestore(&host->lock, flags);

	}



	return IRQ_HANDLED;

}

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