From 99676a5766412f3936c55b9d18565d248e5463ee Mon Sep 17 00:00:00 2001 From: Horatiu Vultur Date: Mon, 17 Apr 2023 09:26:41 +0200 Subject: [PATCH] net: lan966x: Fix lan966x_ifh_get From time to time, it was observed that the nanosecond part of the received timestamp, which is extracted from the IFH, it was actually bigger than 1 second. So then when actually calculating the full received timestamp, based on the nanosecond part from IFH and the second part which is read from HW, it was actually wrong. The issue seems to be inside the function lan966x_ifh_get, which extracts information from an IFH(which is an byte array) and returns the value in a u64. When extracting the timestamp value from the IFH, which starts at bit 192 and have the size of 32 bits, then if the most significant bit was set in the timestamp, then this bit was extended then the return value became 0xffffffff... . And the reason of this is because constants without any postfix are treated as signed longs and that is the reason why '1 << 31' becomes 0xffffffff80000000. This is fixed by adding the postfix 'ULL' to 1. Fixes: fd7627833ddf ("net: lan966x: Stop using packing library") Signed-off-by: Horatiu Vultur Signed-off-by: David S. Miller --- drivers/net/ethernet/microchip/lan966x/lan966x_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c index 9be6462f1cc5..2b6e046e1d10 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c @@ -605,7 +605,7 @@ static u64 lan966x_ifh_get(u8 *ifh, size_t pos, size_t length) v = ifh[IFH_LEN_BYTES - (j / 8) - 1]; if (v & (1 << k)) - val |= (1 << i); + val |= (1ULL << i); } return val; -- 2.11.0