mmc: sdhci: Ignore unexpected CARD_INT interrupts

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>
Cc: <stable@vger.kernel.org>

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 23909804ffb840d3187f21f67180a634a769425e..0def99590d162ebcfb86a16a6b9d5adf96f19cb6 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2733,7 +2733,8 @@ 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;