net: lan966x: Update lan966x_ptp_get_nominal_value

The clk_per_cfg register represents the value added to the system clock
for each clock cycle. The issue is that the default value is wrong,
meaning that in case the DUT was a grandmaster then everone in the
network was too slow. In case there was a grandmaster, then there is no
issue because the DUT will configure clk_per_cfg register based on the
master frequency.

Fixes: 005fbe36a89726 ("net: lan966x: Add support for ptp clocks")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c
index ae782778d6dd44739a3493f65c906522f372bc4a..0a1041da43842181a16b1df3f23d3be433eb500e 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c
@@ -29,10 +29,10 @@ enum {
 
 static u64 lan966x_ptp_get_nominal_value(void)
 {
-       u64 res = 0x304d2df1;
-
-       res <<= 32;
-       return res;
+       /* This is the default value that for each system clock, the time of day
+        * is increased. It has the format 5.59 nanosecond.
+        */
+       return 0x304d4873ecade305;
 }
 
 int lan966x_ptp_hwtstamp_set(struct lan966x_port *port, struct ifreq *ifr)