[tip:timers/core] kselftests: timers: freq-step: Update maximum acceptable precision and errors

[tip-bot for Miroslav Lichvar]

Commit-ID:  d21e43f2ef32ba3242687dbedb3c4b9a76b3eebc
Gitweb:     https://git.kernel.org/tip/d21e43f2ef32ba3242687dbedb3c4b9a76b3eebc
Author:     Miroslav Lichvar <mlichvar@xxxxxxxxxx>
AuthorDate: Tue, 18 Jun 2019 18:06:12 +0200
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sat, 22 Jun 2019 11:28:53 +0200

kselftests: timers: freq-step: Update maximum acceptable precision and errors

PTI has a significant impact on precision of the MONOTONIC_RAW clock,
which prevents a lot of computers from running the freq-step test.
Increase the maximum acceptable precision for the test to not be skipped
to 500 nanoseconds.

After commit 78b98e3c5a66 ("timekeeping/ntp: Determine the multiplier
directly from NTP tick length") the frequency and time errors should be
much smaller. Reduce the maximum acceptable values for the test to pass
to 0.02 ppm and 50 nanoseconds respectively.

Signed-off-by: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Stephen Boyd <stephen.boyd@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190618160612.21957-1-mlichvar@xxxxxxxxxx

---
 tools/testing/selftests/timers/freq-step.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/timers/freq-step.c b/tools/testing/selftests/timers/freq-step.c
index 8cd10662ffba..4b76450d78d1 100644
--- a/tools/testing/selftests/timers/freq-step.c
+++ b/tools/testing/selftests/timers/freq-step.c
@@ -21,9 +21,9 @@
 #define SAMPLE_READINGS 10
 #define MEAN_SAMPLE_INTERVAL 0.1
 #define STEP_INTERVAL 1.0
-#define MAX_PRECISION 100e-9
-#define MAX_FREQ_ERROR 10e-6
-#define MAX_STDDEV 1000e-9
+#define MAX_PRECISION 500e-9
+#define MAX_FREQ_ERROR 0.02e-6
+#define MAX_STDDEV 50e-9
 
 #ifndef ADJ_SETOFFSET
   #define ADJ_SETOFFSET 0x0100