mmc: sdhci: Ignore unexpected CARD_INT interrupts

commit 161e6d44 upstream.

One of our kernelCI boxes hanged at boot because a faulty eSDHC device
was triggering spurious CARD_INT interrupts for SD cards, causing CMD52
reads, which are not allowed for SD devices.  This adds a sanity check
to the interruption path, preventing that illegal command from getting
sent if the CARD_INT interruption should be disabled.

This quirk allows that particular machine to resume boot despite the
faulty hardware, instead of getting hung dealing with thousands of
mishandled interrupts.
Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mmc/host/sdhci.c

@@ -2719,7 +2719,8 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
 		if (intmask & SDHCI_INT_RETUNE)
 			mmc_retune_needed(host->mmc);
 
-		if (intmask & SDHCI_INT_CARD_INT) {
+		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;