]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
net: stmmac: fixed new system time seconds value calculation
authorRoland Hii <roland.king.guan.hii@intel.com>
Wed, 19 Jun 2019 14:13:48 +0000 (22:13 +0800)
committerDavid S. Miller <davem@davemloft.net>
Sat, 22 Jun 2019 23:16:23 +0000 (16:16 -0700)
commita1e5388b4d5fc78688e5e9ee6641f779721d6291
tree8a00323ec0eaa3a272a61aaeb5389d57ae28d54e
parentaad1dcc4f011ea409850e040363dff1e59aa4175
net: stmmac: fixed new system time seconds value calculation

When ADDSUB bit is set, the system time seconds field is calculated as
the complement of the seconds part of the update value.

For example, if 3.000000001 seconds need to be subtracted from the
system time, this field is calculated as
2^32 - 3 = 4294967296 - 3 = 0x100000000 - 3 = 0xFFFFFFFD

Previously, the 0x100000000 is mistakenly written as 100000000.

This is further simplified from
  sec = (0x100000000ULL - sec);
to
  sec = -sec;

Fixes: ba1ffd74df74 ("stmmac: fix PTP support for GMAC4")
Signed-off-by: Roland Hii <roland.king.guan.hii@intel.com>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c