[PATCH] InfiniBand/mthca: don't write ECR in MSI-X mode

From: "Michael S. Tsirkin" <mst@mellanox.co.il>

We don't need to write to the ECR to clear events when using MSI-X, since we
never read the ECR anyway.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/infiniband/hw/mthca/mthca_eq.c

@@ -381,7 +381,6 @@ static irqreturn_t mthca_msi_x_interrupt(int irq, void *eq_ptr,
 	struct mthca_eq  *eq  = eq_ptr;
 	struct mthca_dev *dev = eq->dev;
 
-	writel(eq->ecr_mask, dev->hcr + MTHCA_ECR_CLR_OFFSET + 4);
 	mthca_eq_int(dev, eq);
 
 	/* MSI-X vectors always belong to us */