dm: rtc: Try to avoid a race in rtc_set_get test

It seems that the time can change in between getting it and reading the
offset. Check for this and try again if this happens.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/test/dm/rtc.c b/test/dm/rtc.c
index e23905b..50086ff 100644 (file)
--- a/test/dm/rtc.c
+++ b/test/dm/rtc.c
@@ -60,16 +60,27 @@ static int dm_test_rtc_set_get(struct unit_test_state *uts)
 {
        struct rtc_time now, time, cmp;
        struct udevice *dev, *emul;
-       long offset, old_offset, old_base_time;
+       long offset, check_offset, old_offset, old_base_time;
+       int i;
 
        ut_assertok(uclass_get_device(UCLASS_RTC, 0, &dev));
-       ut_assertok(dm_rtc_get(dev, &now));
 
        ut_assertok(i2c_emul_find(dev, &emul));
        ut_assertnonnull(emul);
 
-       /* Tell the RTC to go into manual mode */
-       old_offset = sandbox_i2c_rtc_set_offset(emul, false, 0);
+       /* Get the offset, putting the RTC into manual mode */
+       i = 0;
+       do {
+               check_offset = sandbox_i2c_rtc_set_offset(emul, false, 0);
+               ut_assertok(dm_rtc_get(dev, &now));
+
+               /* Tell the RTC to go into manual mode */
+               old_offset = sandbox_i2c_rtc_set_offset(emul, false, 0);
+
+               /* If the times changed in that period, read it again */
+       } while (++i < 2 && check_offset != old_offset);
+       ut_asserteq(check_offset, old_offset);
+
        old_base_time = sandbox_i2c_rtc_get_set_base_time(emul, -1);
 
        memset(&time, '\0', sizeof(time));
@@ -127,7 +138,8 @@ static int dm_test_rtc_set_get(struct unit_test_state *uts)
                ut_asserteq(now.tm_sec + 1, cmp.tm_sec);
        }
 
-       old_offset = sandbox_i2c_rtc_set_offset(emul, true, 0);
+       /* return RTC to normal mode */
+       sandbox_i2c_rtc_set_offset(emul, true, 0);
 
        return 0;
 }