vme: tsi148: Only store VME bus errors if they will be checked

The TSI148 driver provides an optional mechanism for ensuring that errors
resulting from posted transfers are caught whilst still relevant. To do this
errors are stored in a link list. If bus errors are not checked, this list
would grow until available memory had been exhausted.

Only store the errors in a link list if error detection is switched on.
Reported-by: De Roo, Steven <steven.deroo@arcelormittal.com>
Signed-off-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/vme/bridges/vme_tsi148.c

@@ -169,7 +169,7 @@ static u32 tsi148_VERR_irqhandler(struct vme_bridge *tsi148_bridge)
 	unsigned int error_addr_high, error_addr_low;
 	unsigned long long error_addr;
 	u32 error_attrib;
-	struct vme_bus_error *error;
+	struct vme_bus_error *error = NULL;
 	struct tsi148_driver *bridge;
 
 	bridge = tsi148_bridge->driver_priv;
@@ -186,16 +186,22 @@ static u32 tsi148_VERR_irqhandler(struct vme_bridge *tsi148_bridge)
 			"Occurred\n");
 	}
 
+	if (err_chk) {
 		error = kmalloc(sizeof(struct vme_bus_error), GFP_ATOMIC);
 		if (error) {
 			error->address = error_addr;
 			error->attributes = error_attrib;
 			list_add_tail(&error->list, &tsi148_bridge->vme_errors);
 		} else {
-		dev_err(tsi148_bridge->parent, "Unable to alloc memory for "
-			"VMEbus Error reporting\n");
-		dev_err(tsi148_bridge->parent, "VME Bus Error at address: "
-			"0x%llx, attributes: %08x\n", error_addr, error_attrib);
+			dev_err(tsi148_bridge->parent,
+				"Unable to alloc memory for VMEbus Error reporting\n");
+		}
+	}
+
+	if (!error) {
+		dev_err(tsi148_bridge->parent,
+			"VME Bus Error at address: 0x%llx, attributes: %08x\n",
+			error_addr, error_attrib);
 	}
 
 	/* Clear Status */