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| author | Gerhard Engleder <gerhard@engleder-embedded.com> | 2025-05-14 21:56:57 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-22 14:29:43 +0200 |
| commit | 6dbf38159d8d4f8009b806b71954daf0a854cb92 (patch) | |
| tree | a469843316cc2958095f196b18ca1b45e9397b96 /net/lapb/lapb_subr.c | |
| parent | a11b8c0be6acd0505a58ff40d474bd778b25b93a (diff) | |
tsnep: fix timestamping with a stacked DSA driver
[ Upstream commit b3ca9eef6646576ad506a96d941d87a69f66732a ]
This driver is susceptible to a form of the bug explained in commit
c26a2c2ddc01 ("gianfar: Fix TX timestamping with a stacked DSA driver")
and in Documentation/networking/timestamping.rst section "Other caveats
for MAC drivers", specifically it timestamps any skb which has
SKBTX_HW_TSTAMP, and does not consider if timestamping has been enabled
in adapter->hwtstamp_config.tx_type.
Evaluate the proper TX timestamping condition only once on the TX
path (in tsnep_xmit_frame_ring()) and store the result in an additional
TX entry flag. Evaluate the new TX entry flag in the TX confirmation path
(in tsnep_tx_poll()).
This way SKBTX_IN_PROGRESS is set by the driver as required, but never
evaluated. SKBTX_IN_PROGRESS shall not be evaluated as it can be set
by a stacked DSA driver and evaluating it would lead to unwanted
timestamps.
Fixes: 403f69bbdbad ("tsnep: Add TSN endpoint Ethernet MAC driver")
Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20250514195657.25874-1-gerhard@engleder-embedded.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/lapb/lapb_subr.c')
0 files changed, 0 insertions, 0 deletions