mmc: sh-mmcif: avoid oops on spurious interrupts

On some systems, e.g., kzm9g, MMCIF interfaces can produce spurious interrupts without any active request. To prevent the Oops, that results in such cases, don't dereference the mmc request pointer until we make sure, that we are indeed processing such a request. Reported-by: Tetsuyuki Kobayashi <[email protected]> Signed-off-by: Guennadi Liakhovetski <[email protected]> Cc: stable <[email protected]> Signed-off-by: Chris Ball <[email protected]>
chewitt · Oct 3, 2012 · 8464dd5 · 8464dd5
1 parent 7a7eb32
commit 8464dd5
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
@@ -1231,6 +1231,10 @@ static irqreturn_t sh_mmcif_intr(int irq, void *dev_id)
 		host->sd_error = true;
 		dev_dbg(&host->pd->dev, "int err state = %08x\n", state);
 	}
+	if (host->state == STATE_IDLE) {
+		dev_info(&host->pd->dev, "Spurious IRQ status 0x%x", state);
+		return IRQ_HANDLED;
+	}
 	if (state & ~(INT_CMD12RBE | INT_CMD12CRE)) {
 		if (!host->dma_active)
 			return IRQ_WAKE_THREAD;