net/mlx5e: Keep HW timestamp stats monotonic across reconfiguration

`mlx5e_stats_ts_get()` currently selects either DMA or port timestamp
counters based on `tx_ptp_opened`. This flag is intentionally kept set
once the PTP TX queues have been opened so their statistics remain
available after queue teardown. As a result, DMA timestamps are no
longer reported after switching from port timestamping back to DMA
timestamping.

The function also reads statistics only from the currently active
channels and TCs. Reducing the number of channels or TCs can therefore
drop previously accumulated timestamp counters from the reported value.

Read the persistent channel statistics instead and always include DMA
timestamp counters. Once the PTP TX queues have been opened, also
include the port timestamp counters.

This also drops state_lock. It previously protected live channel/PTP
pointers, the new code only reads persistent channel_stats and
ptp_stats via mlx5e_stats_nch_read(), which is already safe for
lockless stats access.

Fixes: 3579032c08c1 ("net/mlx5e: Implement ethtool hardware timestamping statistics")
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Shahar Shitrit <shshitrit@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260902193731.3668958-1-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions