So far changing the period by just setting new period values while
running did not work.
The order as indicated by the publicly available reference manual of the i.MX8MP [1]
indicates a sequence:
* initiate the programming sequence
* set the values for PPS period and start time
* start the pulse train generation.
This is currently not used in dwmac5_flex_pps_config(), which instead does:
* initiate the programming sequence and immediately start the pulse train generation
* set the values for PPS period and start time
This caused the period values written not to take effect until the FlexPPS output was
disabled and re-enabled again.
This patch fix the order and allows the period to be set immediately.
[1] https://www.nxp.com/webapp/Download?colCode=IMX8MPRM
Fixes: 9a8a02c9d46d ("net: stmmac: Add Flexible PPS support")
Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
Link: https://lore.kernel.org/r/20230210143937.3427483-1-j.zink@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
4562c65ec8