selftests: drv-net: wait for carrier

On fast machines the tests run in quick succession so even
when tests clean up after themselves the carrier may need
some time to come back.

Specifically in NIPA when ping.py runs right after netpoll_basic.py
the first ping command fails.

Since the context manager callbacks are now common NetDrvEpEnv
gets an ip link up call as well.

Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20250812142054.750282-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 20 insertions, 21 deletions

diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
index 1b8bd648048f..c1f3b608c6d8 100644
--- a/tools/testing/selftests/drivers/net/lib/py/env.py
+++ b/tools/testing/selftests/drivers/net/lib/py/env.py
@@ -4,7 +4,7 @@ import os
 import time
 from pathlib import Path
 from lib.py import KsftSkipEx, KsftXfailEx
-from lib.py import ksft_setup
+from lib.py import ksft_setup, wait_file
 from lib.py import cmd, ethtool, ip, CmdExitFailure
 from lib.py import NetNS, NetdevSimDev
 from .remote import Remote
@@ -25,6 +25,9 @@ class NetDrvEnvBase:
 
         self.env = self._load_env_file()
 
+        # Following attrs must be set be inheriting classes
+        self.dev = None
+
     def _load_env_file(self):
         env = os.environ.copy()
 
@@ -48,6 +51,22 @@ class NetDrvEnvBase:
                 env[pair[0]] = pair[1]
         return ksft_setup(env)
 
+    def __del__(self):
+        pass
+
+    def __enter__(self):
+        ip(f"link set dev {self.dev['ifname']} up")
+        wait_file(f"/sys/class/net/{self.dev['ifname']}/carrier",
+                  lambda x: x.strip() == "1")
+
+        return self
+
+    def __exit__(self, ex_type, ex_value, ex_tb):
+        """
+        __exit__ gets called at the end of a "with" block.
+        """
+        self.__del__()
+
 
 class NetDrvEnv(NetDrvEnvBase):
     """
@@ -72,17 +91,6 @@ class NetDrvEnv(NetDrvEnvBase):
         self.ifname = self.dev['ifname']
         self.ifindex = self.dev['ifindex']
 
-    def __enter__(self):
-        ip(f"link set dev {self.dev['ifname']} up")
-
-        return self
-
-    def __exit__(self, ex_type, ex_value, ex_tb):
-        """
-        __exit__ gets called at the end of a "with" block.
-        """
-        self.__del__()
-
     def __del__(self):
         if self._ns:
             self._ns.remove()
@@ -219,15 +227,6 @@ class NetDrvEpEnv(NetDrvEnvBase):
             raise Exception("Can't resolve remote interface name, multiple interfaces match")
         return v6[0]["ifname"] if v6 else v4[0]["ifname"]
 
-    def __enter__(self):
-        return self
-
-    def __exit__(self, ex_type, ex_value, ex_tb):
-        """
-        __exit__ gets called at the end of a "with" block.
-        """
-        self.__del__()
-
     def __del__(self):
         if self._ns:
             self._ns.remove()