Index: lib/sysfs.c
===================================================================
--- lib/sysfs.c	(revision 5142)
+++ lib/sysfs.c	(working copy)
@@ -591,8 +591,14 @@
 
 	snprintf(linkpath, NAME_MAX, "%s/device", path);
 	dev_len = readlink(linkpath, device, NAME_MAX - 1);
-	if (dev_len < 0)
-		return -SENSORS_ERR_KERNEL;
+	if (dev_len < 0) {
+		/* virtual device without a device link (for example
+		   the acpi thermalzone driver) */
+		err = sensors_read_one_sysfs_chip(path, "virtual", path);
+		if (err < 0)
+			return err;
+		return 0;
+	}
 	device[dev_len] = '\0';
 	device_p = strrchr(device, '/') + 1;