Re: [Linuxptp-users] offset explosion and irregular phc offsets

[Keller, J. E <jac...@in...>]

On Mon, 2013-08-12 at 20:21 +0200, Richard Cochran wrote:
> On Mon, Aug 12, 2013 at 05:58:21PM +0000, Keller, Jacob E wrote:
> > Hi Julien,
> > 
> > It appears you are using the e1000e driver. Could you get me the device
> > IDs for the parts that you are doing 1588/PTP on? I believe that what
> > you are experiencing is actually a driver bug, related to an overflow on
> > one of the timestamp registers. I am not certain if it has been fixed in
> > the version of the kernel you are using...
> 
> Are you talking about the following commit? I had totally forgotten
> about this. It was merged in v3.10, and I don't know offhand which
> stable kernels in went into, if any.
> 
> Thanks,
> Richard
> 
>     commit 73e3dd6b45c4c870fc2641eb04c24e3f12dab1e0
>     Author: Richard Cochran <ric...@gm...>
>     Date:   Tue Apr 23 01:56:34 2013 +0000
> 
>     e1000e: fix numeric overflow in phc settime method
>     
>     The PTP Hardware Clock settime function in the e1000e driver
>     computes nanoseconds from a struct timespec. The code converts the
>     seconds field .tv_sec by multiplying it with NSEC_PER_SEC. However,
>     both operands are of type long, resulting in an unintended overflow.
>     The patch fixes the issue by using the helper function from time.h.
>     
>     CC: stable <st...@vg...>
>     Signed-off-by: Richard Cochran <ric...@gm...>
>     Tested-by: Aaron Brown <aar...@in...>
>     Signed-off-by: Jeff Kirsher <jef...@in...>

This is the type of thing I had in mind. I don't know if this would
cause the issue seen here or not...

At any rate, I believe what I am remembering is actually a change in
igb, not e1000e..

- Jake