HDS mode has confusing semantics. On GET kernel reports effective mode. On SET kernel expects explicit config. Effective mode on GET means that we know the current state, but we don't know if it's a driver default or user setting. This matter because driver default can change automatically when e.g. XDP is attached. Explicit user setting must not be lost. With that in mind, we can't restore the HDS setting like we restore other NIC config. We should always reset to default ("unknown"). This fixes an issue with tests running after the devmem test not being able to attach XDP, e.g. Exception| File "./xdp_metadata.py", line 105, in test_xdp_rss_hash [...] Exception| net.lib.py.utils.CmdExitFailure: Command failed Exception| CMD: ip link set dev ens9np0 xdpdrv pinned /sys/fs/bpf/xdp_metadata_test/xdp_rss_hash Exception| EXIT: 2 Exception| STDERR: Error: unable to install XDP to device using tcp-data-split. not ok 1 xdp_metadata.test_xdp_rss_hash.tcp Signed-off-by: Jakub Kicinski --- CC: shuah@kernel.org CC: hawk@kernel.org CC: john.fastabend@gmail.com CC: sdf@fomichev.me CC: bobbyeshleman@meta.com CC: linux-kselftest@vger.kernel.org --- tools/testing/selftests/drivers/net/hw/devmem_lib.py | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/tools/testing/selftests/drivers/net/hw/devmem_lib.py b/tools/testing/selftests/drivers/net/hw/devmem_lib.py index 0921ff03eb81..4e6316c7de96 100644 --- a/tools/testing/selftests/drivers/net/hw/devmem_lib.py +++ b/tools/testing/selftests/drivers/net/hw/devmem_lib.py @@ -37,14 +37,13 @@ from lib.py import (bkg, cmd, defer, ethtool, rand_port, wait_port_listen, rings = ethnl.rings_get({'header': {'dev-index': cfg.ifindex}}) orig_rx_rings = rings['rx'] orig_hds_thresh = rings.get('hds-thresh', 0) - orig_data_split = rings.get('tcp-data-split', 'unknown') ethnl.rings_set({'header': {'dev-index': cfg.ifindex}, 'tcp-data-split': 'enabled', 'hds-thresh': 0, 'rx': min(64, orig_rx_rings)}) defer(ethnl.rings_set, {'header': {'dev-index': cfg.ifindex}, - 'tcp-data-split': orig_data_split, + 'tcp-data-split': 'unknown', 'hds-thresh': orig_hds_thresh, 'rx': orig_rx_rings}) -- 2.55.0