| From 09004c1b95ddaa4a18d8a220c55b8bbdb1fe338c Mon Sep 17 00:00:00 2001 |
| From: Jacob Keller <jacob.e.keller@intel.com> |
| Date: Mon, 25 Feb 2019 11:20:05 -0800 |
| Subject: i40e: fix i40e_ptp_adjtime when given a negative delta |
| |
| [ 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); |
| -- |
| 2.20.1 |
| |
