mmc: core: Prevent processing SDIO IRQs when the card is suspended

Processing of SDIO IRQs must obviously be prevented while the card is system suspended, otherwise we may end up trying to communicate with an uninitialized SDIO card. Reports throughout the years shows that this is not only a theoretical problem, but a real issue. So, let's finally fix this problem, by keeping track of the state for the card and bail out before processing the SDIO IRQ, in case the card is suspended. Cc: [email protected] Reported-by: Douglas Anderson <[email protected]> Tested-by: Douglas Anderson <[email protected]> Signed-off-by: Ulf Hansson <[email protected]>
jangid · Jun 18, 2019 · 8329338 · 8329338
1 parent 0f7b79a
commit 8329338
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
@@ -937,6 +937,10 @@ static int mmc_sdio_pre_suspend(struct mmc_host *host)
  */
 static int mmc_sdio_suspend(struct mmc_host *host)
 {
+	/* Prevent processing of SDIO IRQs in suspended state. */
+	mmc_card_set_suspended(host->card);
+	cancel_delayed_work_sync(&host->sdio_irq_work);
+
 	mmc_claim_host(host);
 
 	if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host))
@@ -985,13 +989,20 @@ static int mmc_sdio_resume(struct mmc_host *host)
 		err = sdio_enable_4bit_bus(host->card);
 	}
 
-	if (!err && host->sdio_irqs) {
+	if (err)
+		goto out;
+
+	/* Allow SDIO IRQs to be processed again. */
+	mmc_card_clr_suspended(host->card);
+
+	if (host->sdio_irqs) {
 		if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD))
 			wake_up_process(host->sdio_irq_thread);
 		else if (host->caps & MMC_CAP_SDIO_IRQ)
 			host->ops->enable_sdio_irq(host, 1);
 	}
 
+out:
 	mmc_release_host(host);
 
 	host->pm_flags &= ~MMC_PM_KEEP_POWER;

diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
@@ -34,6 +34,10 @@ static int process_sdio_pending_irqs(struct mmc_host *host)
 	unsigned char pending;
 	struct sdio_func *func;
 
+	/* Don't process SDIO IRQs if the card is suspended. */
+	if (mmc_card_suspended(card))
+		return 0;
+
 	/*
 	 * Optimization, if there is only 1 function interrupt registered
 	 * and we know an IRQ was signaled then call irq handler directly.