4.14-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Poirier bpoirier@suse.com
[ Upstream commit fff200caf6f9179dd9a7fc67acd659e614c3f72f ]
There have been multiple reports of crashes that look like kernel: RIP: 0010:[<ffffffff8110303f>] timecounter_read+0xf/0x50 [...] kernel: Call Trace: kernel: [<ffffffffa0806b0f>] e1000e_phc_gettime+0x2f/0x60 [e1000e] kernel: [<ffffffffa0806c5d>] e1000e_systim_overflow_work+0x1d/0x80 [e1000e] kernel: [<ffffffff810992c5>] process_one_work+0x155/0x440 kernel: [<ffffffff81099e16>] worker_thread+0x116/0x4b0 kernel: [<ffffffff8109f422>] kthread+0xd2/0xf0 kernel: [<ffffffff8163184f>] ret_from_fork+0x3f/0x70
These can be traced back to the fact that e1000e_systim_reset() skips the timecounter_init() call if e1000e_get_base_timinca() returns -EINVAL, which leads to a null deref in timecounter_read().
Commit 83129b37ef35 ("e1000e: fix systim issues", v4.2-rc1) reworked e1000e_get_base_timinca() in such a way that it can return -EINVAL for e1000_pch_spt if the SYSCFI bit is not set in TSYNCRXCTL.
Some experimentation has shown that on I219 (e1000_pch_spt, "MAC: 12") adapters, the E1000_TSYNCRXCTL_SYSCFI flag is unstable; TSYNCRXCTL reads sometimes don't have the SYSCFI bit set. Retrying the read shortly after finds the bit to be set. This was observed at boot (probe) but also link up and link down.
Moreover, the phc (PTP Hardware Clock) seems to operate normally even after reads where SYSCFI=0. Therefore, remove this register read and unconditionally set the clock parameters.
Reported-by: Achim Mildenberger admin@fph.physik.uni-karlsruhe.de Message-Id: 20180425065243.g5mqewg5irkwgwgv@f2 Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1075876 Fixes: 83129b37ef35 ("e1000e: fix systim issues") Signed-off-by: Benjamin Poirier bpoirier@suse.com Tested-by: Aaron Brown aaron.f.brown@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/intel/e1000e/netdev.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -3558,15 +3558,12 @@ s32 e1000e_get_base_timinca(struct e1000 } break; case e1000_pch_spt: - if (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI) { - /* Stable 24MHz frequency */ - incperiod = INCPERIOD_24MHZ; - incvalue = INCVALUE_24MHZ; - shift = INCVALUE_SHIFT_24MHZ; - adapter->cc.shift = shift; - break; - } - return -EINVAL; + /* Stable 24MHz frequency */ + incperiod = INCPERIOD_24MHZ; + incvalue = INCVALUE_24MHZ; + shift = INCVALUE_SHIFT_24MHZ; + adapter->cc.shift = shift; + break; case e1000_pch_cnp: if (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI) { /* Stable 24MHz frequency */