Re: [Intel-wired-lan] [PATCH net] e1000e: fix PTP on e1000_pch_lpt variants

From: Rustad, Mark D
Date: Tue Jul 19 2016 - 16:49:23 EST

Jarod Wilson <jarod@xxxxxxxxxx> wrote:

I've got reports that the Intel I-218V NIC in Intel NUC5i5RYH systems used
as a PTP slave experiences random ~10 hour clock jumps, which are resolved
if the same workaround for the 82574 and 82583 is employed. Switching from
an if to a select, because the list of NIC types could well grow further
and we'd already have to wrap the conditionals.

CC: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
CC: intel-wired-lan@xxxxxxxxxxxxxxxx
CC: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Jarod Wilson <jarod@xxxxxxxxxx>
drivers/net/ethernet/intel/e1000e/netdev.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 2b2e2f8..866fea0 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -4335,7 +4335,10 @@ static cycle_t e1000e_cyclecounter_read(const struct cyclecounter *cc)
systim = (cycle_t)systimel;
systim |= (cycle_t)systimeh << 32;

- if ((hw->mac.type == e1000_82574) || (hw->mac.type == e1000_82583)) {
+ switch (hw->mac.type) {
+ case e1000_82574:
+ case e1000_82583:
+ case e1000_pch_lpt:
u64 time_delta, rem, temp;
u32 incvalue;
int i;

I don't think that it is acceptable to declare local variables inside a switch statement quite like this. At a minimum, a new block needs to be opened to allow the declarations.

@@ -4360,6 +4363,9 @@ static cycle_t e1000e_cyclecounter_read(const struct cyclecounter *cc)
(rem == 0))
+ break;
+ default:
+ break;
return systim;

Mark Rustad, Networking Division, Intel Corporation

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