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| author | Miquel Raynal <miquel.raynal@bootlin.com> | 2023-02-14 14:50:33 +0100 |
|---|---|---|
| committer | Stefan Schmidt <stefan@datenfreihafen.org> | 2023-02-18 16:44:53 +0100 |
| commit | 1375e3ba9d773f2dbac96ebddfdd0d160276ca40 (patch) | |
| tree | 127339b391bab4a0e043e9e44975206fc051c23c /net/mac802154 | |
| parent | 1edecbd0bd45c9c899e0f82b123342f28423468c (diff) | |
| download | linux-1375e3ba9d773f2dbac96ebddfdd0d160276ca40.tar.gz linux-1375e3ba9d773f2dbac96ebddfdd0d160276ca40.tar.bz2 linux-1375e3ba9d773f2dbac96ebddfdd0d160276ca40.zip | |
mac802154: Send beacons using the MLME Tx path
Using ieee802154_subif_start_xmit() to bypass the net queue when
sending beacons is broken because it does not acquire the
HARD_TX_LOCK(), hence not preventing datagram buffers to be smashed by
beacons upon contention situation. Using the mlme_tx helper is not the
best fit either but at least it is not buggy and has little-to-no
performance hit. More details are given in the comment explaining this
choice in the code.
Fixes: 3accf4762734 ("mac802154: Handle basic beaconing")
Reported-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230214135035.1202471-5-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Diffstat (limited to 'net/mac802154')
| -rw-r--r-- | net/mac802154/scan.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c index 8f98efec7753..fff41e59099e 100644 --- a/net/mac802154/scan.c +++ b/net/mac802154/scan.c @@ -326,7 +326,25 @@ static int mac802154_transmit_beacon(struct ieee802154_local *local, return ret; } - return ieee802154_subif_start_xmit(skb, sdata->dev); + /* Using the MLME transmission helper for sending beacons is a bit + * overkill because we do not really care about the final outcome. + * + * Even though, going through the whole net stack with a regular + * dev_queue_xmit() is not relevant either because we want beacons to be + * sent "now" rather than go through the whole net stack scheduling + * (qdisc & co). + * + * Finally, using ieee802154_subif_start_xmit() would only be an option + * if we had a generic transmit helper which would acquire the + * HARD_TX_LOCK() to prevent buffer handling conflicts with regular + * packets. + * + * So for now we keep it simple and send beacons with our MLME helper, + * even if it stops the ieee802154 queue entirely during these + * transmissions, wich anyway does not have a huge impact on the + * performances given the current design of the stack. + */ + return ieee802154_mlme_tx(local, sdata, skb); } void mac802154_beacon_worker(struct work_struct *work) |