Patch "mmc: sdhci: Ignore unexpected CARD_INT interrupts" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

mmc: sdhci: Ignore unexpected CARD_INT interrupts

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mmc-sdhci-ignore-unexpected-card_int-interrupts.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Gabriel Krisman Bertazi <[email protected]>
Date: Mon, 16 Jan 2017 12:23:42 -0200
Subject: mmc: sdhci: Ignore unexpected CARD_INT interrupts

From: Gabriel Krisman Bertazi <[email protected]>

commit 161e6d44a5e2d3f85365cb717d60e363171b39e6 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.

---
 drivers/mmc/host/sdhci.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -2629,7 +2629,8 @@ static irqreturn_t sdhci_irq(int irq, vo
 			pr_err("%s: Card is consuming too much power!\n",
 				mmc_hostname(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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/mmc-sdhci-ignore-unexpected-card_int-interrupts.patch