From 83293386bc95cf5e9f0c0175794455835bd1cb4a Mon Sep 17 00:00:00 2001
From: Ulf Hansson <ulf.hansson@linaro.org>
Date: Tue, 18 Jun 2019 14:05:17 +0200
Subject: [PATCH] mmc: core: Prevent processing SDIO IRQs when the card is suspended
Git-commit: 83293386bc95cf5e9f0c0175794455835bd1cb4a
Patch-mainline: v5.2-rc6
References: bsc#1051510

[ Backport note: cancel_delayed_work_sync() call in mmc_sdio_suspend()
  is commented out, as the work doesn't exist in SLE15 code ]

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: stable@vger.kernel.org
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/mmc/core/sdio.c     |   13 ++++++++++++-
 drivers/mmc/core/sdio_irq.c |    4 ++++
 2 files changed, 16 insertions(+), 1 deletion(-)

--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -907,6 +907,10 @@ static int mmc_sdio_pre_suspend(struct m
  */
 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))
@@ -962,13 +966,20 @@ static int mmc_sdio_resume(struct mmc_ho
 		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;
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -38,6 +38,10 @@ static int process_sdio_pending_irqs(str
 	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.