cbus-retu: Add locking around register access in irq handler

Commit Message

Michael Buesch Feb. 28, 2011, 4:06 p.m. UTC

None

Patch

Index: linux-omap-2.6/drivers/cbus/retu.c
===================================================================
--- linux-omap-2.6.orig/drivers/cbus/retu.c	2011-02-28 16:59:10.767302605 +0100
+++ linux-omap-2.6/drivers/cbus/retu.c	2011-02-28 16:59:58.629389762 +0100
@@ -198,10 +198,12 @@  static irqreturn_t retu_irq_handler(int
 	u16			idr;
 	u16			imr;
 
+	mutex_lock(&retu->mutex);
 	idr = __retu_read_reg(retu, RETU_REG_IDR);
 	imr = __retu_read_reg(retu, RETU_REG_IMR);
-	idr &= ~imr;
+	mutex_unlock(&retu->mutex);
 
+	idr &= ~imr;
 	if (!idr) {
 		dev_vdbg(retu->dev, "No IRQ, spurious?\n");
 		return IRQ_NONE;