mmc: sh-mmcif: avoid oops on spurious interrupts

lyakh · gregkh · commit 8c63c3bf3e32 · 2012-10-13T05:50:34.000+09:00
commit 8464dd5 upstream. 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 <koba@kmckk.co.jp> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
@@ -1229,6 +1229,10 @@ 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;
