> -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-boun...@lists.osuosl.org] On > Behalf Of Neftin, Sasha > Sent: Monday, February 27, 2017 12:40 AM > To: Bernd Faust <berndfa...@gmail.com>; Kirsher, Jeffrey T > <jeffrey.t.kirs...@intel.com>; intel-wired-...@lists.osuosl.org; > netdev@vger.kernel.org; linux-ker...@vger.kernel.org > Subject: Re: [Intel-wired-lan] [PATCH] e1000e: fix timing for 82579 Gigabit > Ethernet controller > > On 2/26/2017 11:08, Neftin, Sasha wrote: > > On 2/19/2017 14:55, Neftin, Sasha wrote: > >> On 2/16/2017 20:42, Bernd Faust wrote: > >>> After an upgrade to Linux kernel v4.x the hardware timestamps of the > >>> 82579 Gigabit Ethernet Controller are different than expected. > >>> The values that are being read are almost four times as big as before > >>> the kernel upgrade. > >>> > >>> The difference is that after the upgrade the driver sets the clock > >>> frequency to 25MHz, where before the upgrade it was set to 96MHz. Intel > >>> confirmed that the correct frequency for this network adapter is 96MHz. > >>> > >>> Signed-off-by: Bernd Faust <berndfa...@gmail.com> > >>> --- > >>> drivers/net/ethernet/intel/e1000e/netdev.c | 6 ++++++ > >>> 1 file changed, 6 insertions(+) > >>> > >>> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c > >>> b/drivers/net/ethernet/intel/e1000e/netdev.c > >>> index 7017281..8b7113d 100644 > >>> --- a/drivers/net/ethernet/intel/e1000e/netdev.c > >>> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c > >>> @@ -3511,6 +3511,12 @@ s32 e1000e_get_base_timinca(struct > >>> e1000_adapter *adapter, u32 *timinca) > >>> > >>> switch (hw->mac.type) { > >>> case e1000_pch2lan: > >>> + /* Stable 96MHz frequency */ > >>> + incperiod = INCPERIOD_96MHz; > >>> + incvalue = INCVALUE_96MHz; > >>> + shift = INCVALUE_SHIFT_96MHz; > >>> + adapter->cc.shift = shift + INCPERIOD_SHIFT_96MHz; > >>> + break; > >>> case e1000_pch_lpt: > >>> if (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI) { > >>> /* Stable 96MHz frequency */ > >>> -- > >>> 2.7.4 > >>> _______________________________________________ > >>> Intel-wired-lan mailing list > >>> intel-wired-...@lists.osuosl.org > >>> http://lists.osuosl.org/mailman/listinfo/intel-wired-lan > >> > >> Hello, > >> > >> e1000_pch2lan mac type corresponds to 82579LM and 82579V network > >> adapters. System clock frequency indication (SYSCFI) for these > >> devices supports both 25MHz and 96MHz frequency. By default > >> TSYNCRXCTL.SYSCFI is set to 1 and that means 96MHz frequency is picked. > >> > >> It is better to keep the current implementation as it covers all > >> options. > >> > >> Thanks, > >> > >> Sasha > >> > > Hello, > > > > During last couple of weeks I saw few complaints from community on > > same timing problem with 82579. I will double check clock definition > > with HW architecture. > > > > Sasha > > > I've double checked - 82579 support 96MHz frequency only. So, let's > accept this suggestion to upstream. > > Ack. >
This resolves also a complaint from someone on the LinuxPTP development mailing list. ACK. Thanks, Jake
