[PATCH net 1/4] net: lan966x: Update lan966x_ptp_get_nominal_value

From: Horatiu Vultur
Date: Sat Apr 09 2022 - 14:39:26 EST


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: d096459494a887 ("net: lan966x: Add support for ptp clocks")
Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c
index ae782778d6dd..0a1041da4384 100644
--- 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)
--
2.33.0