net: stmmac: do not overwrite phc_index when no PTP clock is registered

stmmac_get_ts_info() reports phc_index as 0 when hardware timestamping
is supported but no PTP clock has been registered yet (e.g. while the
interface is down). Zero is a valid PHC index and would make userspace
resolve the wrong clock; the absence of a clock should be reported as
-1.

The ethtool core already initializes phc_index to -1 before invoking
the get_ts_info callback (ethtool_init_tsinfo()), so just drop the
erroneous assignment.

Fixes: 9364fa7fcf12 ("net: stmmac: Remove setting of RX software timestamp")
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20260914-stmmac-fix-phc_index-v2-1-bf3d90373fe4@oss.qualcomm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions