dm: rtc: Avoid a race in the rtc_reset test

Since resetting the RTC on sandbox causes it to read the base time from
the system, we cannot rely on this being unchanged since it was last read.
Allow for a one-second delay.

Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Fixes: https://source.denx.de/u-boot/u-boot/-/issues/4
Reported-by: Bin Meng <bmeng.cn@gmail.com>
Reported-by: Tom Rini <trini@konsulko.com>
Suggested-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/test/dm/rtc.c b/test/dm/rtc.c
index a8349756c18fe28d0c748468a7a42738eea8138c..e23905b3e2ec442064115f89e74a517ec0c627d3 100644 (file)
--- a/test/dm/rtc.c
+++ b/test/dm/rtc.c
@@ -251,10 +251,15 @@ static int dm_test_rtc_reset(struct unit_test_state *uts)
 
        ut_asserteq(0, sandbox_i2c_rtc_get_set_base_time(emul, -1));
 
-       /* Resetting the RTC should put he base time back to normal */
+       /*
+        * Resetting the RTC should put the base time back to normal. Allow for
+        * a one-second adjustment in case the time flips over while this
+        * test process is pre-empted, since reset_time() in i2c_rtc_emul.c
+        * reads the time from the OS.
+        */
        ut_assertok(dm_rtc_reset(dev));
        base_time = sandbox_i2c_rtc_get_set_base_time(emul, -1);
-       ut_asserteq(old_base_time, base_time);
+       ut_assert(base_time - old_base_time <= 1);
 
        return 0;
 }