selftests: timers: set-timer-lat: Fix hang when testing unsupported alarms

When timer_create() fails on a bootime or realtime clock, setup_timer()
returns 0 as if timer has been set. Callers wait forever for the timer
to expire.

This hang is seen on a system that doesn't have support for:

CLOCK_REALTIME_ALARM   ABSTIME missing CAP_WAKE_ALARM? : [UNSUPPORTED]

Test hangs waiting for a timer that hasn't been set to expire. Fix
setup_timer() to return 1, add handling in callers to detect the
unsupported case and return 0 without waiting to not fail the test.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

diff --git a/tools/testing/selftests/timers/set-timer-lat.c b/tools/testing/selftests/timers/set-timer-lat.c
index ea1af5dbc7b6d8c29196c51109a401091213bdda..50da45437daab0b5785a4925ac793644cb9d02fd 100644 (file)
--- a/tools/testing/selftests/timers/set-timer-lat.c
+++ b/tools/testing/selftests/timers/set-timer-lat.c
@@ -143,7 +143,8 @@ int setup_timer(int clock_id, int flags, int interval, timer_t *tm1)
                        printf("%-22s %s missing CAP_WAKE_ALARM?    : [UNSUPPORTED]\n",
                                        clockstring(clock_id),
                                        flags ? "ABSTIME":"RELTIME");
-                       return 0;
+                       /* Indicate timer isn't set, so caller doesn't wait */
+                       return 1;
                }
                printf("%s - timer_create() failed\n", clockstring(clock_id));
                return -1;
@@ -213,8 +214,9 @@ int do_timer(int clock_id, int flags)
        int err;
 
        err = setup_timer(clock_id, flags, interval, &tm1);
+       /* Unsupported case - return 0 to not fail the test */
        if (err)
-               return err;
+               return err == 1 ? 0 : err;
 
        while (alarmcount < 5)
                sleep(1);
@@ -231,8 +233,9 @@ int do_timer_oneshot(int clock_id, int flags)
        int err;
 
        err = setup_timer(clock_id, flags, interval, &tm1);
+       /* Unsupported case - return 0 to not fail the test */
        if (err)
-               return err;
+               return err == 1 ? 0 : err;
 
        memset(&timeout, 0, sizeof(timeout));
        timeout.tv_sec = 5;