[PATCH net-next v3 2/6] selftests: drv-net: give HW stats sync time extra 25% of margin

[Jakub Kicinski <kuba@kernel.org>]

There are transient failures for devices which update stats
periodically, especially if it's the FW DMA'ing the stats
rather than host periodic work querying the FW. Wait 25%
longer than strictly necessary.

For devices which don't report stats-block-usecs we retain
25 msec as the default wait time (0.025sec == 20,000usec * 1.25).

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/testing/selftests/drivers/net/lib/py/env.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
index ccff345fe1c1..6a71c7e7f136 100644
--- a/tools/testing/selftests/drivers/net/lib/py/env.py
+++ b/tools/testing/selftests/drivers/net/lib/py/env.py
@@ -288,8 +288,8 @@ from . import bpftool, RtnlFamily, Netlink
                 if "Operation not supported" not in e.cmd.stderr:
                     raise
 
-            self._stats_settle_time = 0.025 + \
-                data.get('stats-block-usecs', 0) / 1000 / 1000
+            self._stats_settle_time = \
+                1.25 * data.get('stats-block-usecs', 20000) / 1000 / 1000
 
         time.sleep(self._stats_settle_time)
 
-- 
2.53.0