memory: tegra20-mc: Fix hang in IRQ handler.

In Tegra20 any memory controller interrupt would cause an
infinite loop in the IRQ handler.

Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/memory/tegra20-mc.c b/drivers/memory/tegra20-mc.c
index 2ca5f2814f4a..0548eeacd573 100644
--- a/drivers/memory/tegra20-mc.c
+++ b/drivers/memory/tegra20-mc.c
@@ -193,8 +193,11 @@ static irqreturn_t tegra20_mc_isr(int irq, void *data)
         mask &= stat;
         if (!mask)
                 return IRQ_NONE;
-        while ((bit = ffs(mask)) != 0)
+        while ((bit = ffs(mask)) != 0) {
                 tegra20_mc_decode(mc, bit - 1);
+                mask &= ~BIT(bit - 1);
+        }
+
         mc_writel(mc, stat, MC_INTSTATUS);
         return IRQ_HANDLED;
 }