[PATCH 1/7] [Bionic] thunderbolt: Handle NULL boot ACL entries properly

[Kai-Heng Feng]

From: Mika Westerberg <mika.westerberg at linux.intel.com>

BugLink: https://bugs.launchpad.net/bugs/1789358

If the boot ACL entry is already NULL we should not fill in the upper
two DWs with 0xfffffffff. Otherwise they are not shown as empty entries
when the sysfs attribute is read.

Fixes: 9aaa3b8b4c56 ("thunderbolt: Add support for preboot ACL")
Signed-off-by: Mika Westerberg <mika.westerberg at linux.intel.com>
Acked-by: Yehezkel Bernat <yehezkelshb at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit dd010bd7af6248b40ab31640a6e31fbebea5aa22)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/thunderbolt/icm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index 2d2ceda9aa26..500911f16498 100644
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -1255,7 +1255,7 @@ static int icm_ar_get_boot_acl(struct tb *tb, uuid_t *uuids, size_t nuuids)
 			/* Map empty entries to null UUID */
 			uuid[0] = 0;
 			uuid[1] = 0;
-		} else {
+		} else if (uuid[0] != 0 || uuid[1] != 0) {
 			/* Upper two DWs are always one's */
 			uuid[2] = 0xffffffff;
 			uuid[3] = 0xffffffff;
-- 
2.17.1