net: mscc: ocelot: don't downgrade timestamping RX filters in SIOCSHWTSTAMP
authorVladimir Oltean <vladimir.oltean@nxp.com>
Fri, 26 Nov 2021 17:28:41 +0000 (19:28 +0200)
committerJakub Kicinski <kuba@kernel.org>
Fri, 26 Nov 2021 19:38:20 +0000 (11:38 -0800)
commit8a075464d1e9317ffae0973dfe538a7511291a06
tree9a2b8934dd7993cbee1a2332f804ff704860bf78
parentb32e521eb5342dc2b1ab60a6aee15b534b2f1430
net: mscc: ocelot: don't downgrade timestamping RX filters in SIOCSHWTSTAMP

The ocelot driver, when asked to timestamp all receiving packets, 1588
v1 or NTP, says "nah, here's 1588 v2 for you".

According to this discussion:
https://patchwork.kernel.org/project/netdevbpf/patch/20211104133204.19757-8-martin.kaistra@linutronix.de/#24577647
drivers that downgrade from a wider request to a narrower response (or
even a response where the intersection with the request is empty) are
buggy, and should return -ERANGE instead. This patch fixes that.

Fixes: 4e3b0468e6d7 ("net: mscc: PTP Hardware Clock (PHC) support")
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/ethernet/mscc/ocelot.c