[PATCH net 2/2] selftests: drv-net: ring_reconfig: skip tx stall test without channel config

["Bilal Yazıcıoğlu" <ahmetbilalyazicioglu@gmail.com>]

reconfig_tx_stall() needs at least two combined channels and already
skips devices which don't report enough of them. On devices whose
driver doesn't implement the ethtool get_channels op (e.g. e1000e)
the initial channels_get call fails with -EOPNOTSUPP instead, which
YNL raises as an NlError, so the test is reported as a failure.

Use the _channels_get_or_skip() helper to skip the test in that case
as well. Other netlink errors are still reported as failures.

The issue was found through AI-assisted source code analysis
(OpenAI Codex) and confirmed on a ThinkPad T480 with an Intel I219-V
(e1000e, 8086:15d8). As for the previous patch, the test function
was run against that device with a stub environment and ethtool set
requests blocked, and is now skipped.

Fixes: c98610c2eb70 ("selftests: drv-net: Test queue stall upon reconfig")
Signed-off-by: Bilal Yazıcıoğlu <ahmetbilalyazicioglu@gmail.com>
---
 tools/testing/selftests/drivers/net/ring_reconfig.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/drivers/net/ring_reconfig.py b/tools/testing/selftests/drivers/net/ring_reconfig.py
index baac20e8d3e..dd6ff6b2b64 100755
--- a/tools/testing/selftests/drivers/net/ring_reconfig.py
+++ b/tools/testing/selftests/drivers/net/ring_reconfig.py
@@ -319,7 +319,7 @@ def reconfig_tx_stall(cfg) -> None:
     other_queue = 0
 
     ehdr = {'header': {'dev-index': cfg.ifindex}}
-    chans = cfg.eth.channels_get(ehdr)
+    chans = _channels_get_or_skip(cfg, ehdr)
 
     if "combined-max" not in chans:
         raise KsftSkipEx("device does not support combined channels")
-- 
2.56.0