From: Jacob Keller jacob.e.keller@intel.com
[ Upstream commit b3ccbbce1e455b8454d3935eb9ae0a5f18939e24 ]
Commit 0ac30ce43323 ("i40e: fix up 32 bit timespec references", 2017-07-26) claims to be cleaning up references to 32-bit timespecs.
The actual contents of the commit make no sense, as it converts a call to timespec64_add into timespec64_add_ns. This would seem ok, if (a) the change was documented in the commit message, and (b) timespec64_add_ns supported negative numbers.
timespec64_add_ns doesn't work with signed deltas, because the implementation is based around iter_div_u64_rem. This change resulted in a regression where i40e_ptp_adjtime would interpret small negative adjustments as large positive additions, resulting in incorrect behavior.
This commit doesn't appear to fix anything, is not well explained, and introduces a bug, so lets just revert it.
Reverts: 0ac30ce43323 ("i40e: fix up 32 bit timespec references", 2017-07-26) Signed-off-by: Jacob Keller jacob.e.keller@intel.com Reviewed-by: Arnd Bergmann arnd@arndb.de Tested-by: Andrew Bowers andrewx.bowers@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Sasha Levin (Microsoft) sashal@kernel.org --- drivers/net/ethernet/intel/i40e/i40e_ptp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c index 5fb4353c742b..31575c0bb884 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c @@ -146,12 +146,13 @@ static int i40e_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) static int i40e_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) { struct i40e_pf *pf = container_of(ptp, struct i40e_pf, ptp_caps); - struct timespec64 now; + struct timespec64 now, then;
+ then = ns_to_timespec64(delta); mutex_lock(&pf->tmreg_lock);
i40e_ptp_read(pf, &now, NULL); - timespec64_add_ns(&now, delta); + now = timespec64_add(now, then); i40e_ptp_write(pf, (const struct timespec64 *)&now);
mutex_unlock(&pf->tmreg_lock);