RE: [PATCH net-next V3 13/23] ptp: igb: convert to the 64 bit get/set time methods.

[Keller, Jacob E]

> -----Original Message-----
> From: Richard Cochran [mailto:richardcochran@xxxxxxxxx]
> Sent: Tuesday, March 31, 2015 2:37 PM
> To: Keller, Jacob E
> Cc: thomas.lendacky@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> baolin.wang@xxxxxxxxxx; b45643@xxxxxxxxxxxxx; sshah@xxxxxxxxxxxxxx;
> amirv@xxxxxxxxxxxx; ben@xxxxxxxxxxxxxxx; sonic.zhang@xxxxxxxxxx;
> peppe.cavallaro@xxxxxx; Allan, Bruce W; rayagond@xxxxxxxxxxxxxxx;
> tglx@xxxxxxxxxxxxx; ariel.elior@xxxxxxxxxx; cmetcalf@xxxxxxxxxx; Vick,
> Matthew; linux-net-drivers@xxxxxxxxxxxxxx; arnd@xxxxxxxxxx;
> Frank.Li@xxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; mchan@xxxxxxxxxxxx;
> Wyborny, Carolyn; prashant@xxxxxxxxxxxx; davem@xxxxxxxxxxxxx;
> Kirsher, Jeffrey T; stefan.sorensen@xxxxxxxxxxxxxxx; john.stultz@xxxxxxxxxx
> Subject: Re: [PATCH net-next V3 13/23] ptp: igb: convert to the 64 bit
> get/set time methods.
> 
> On Tue, Mar 31, 2015 at 09:08:10PM +0000, Keller, Jacob E wrote:
> > On Sun, 2015-03-29 at 23:12 +0200, Richard Cochran wrote:
> > > For the 82576, the driver's clock is implemented using a timecounter,
> > > and so with this patch that device is ready for the year 2038.
> > >
> > > However, in the case of the i210, the device stores the number of
> > > seconds in a 32 bit register.  Therefore, more work is needed on this
> > > driver before the year 2038 comes around.
> > >
> > > Compile tested only.
> >
> > I assume we would want to use a time counter wrapper here to resolve
> > this issue?
> 
> I would just keep the seconds in software for settime() and adjtime(),
> but let the nanoseconds field go to the hardware.  Then, the gettime()
> result, the periodic outputs, the external time stamps, and the skb
> time stamps will need to be corrected by that many seconds.
> 
> Thanks,
> Richard

That seems reasonable.

Regards,
Jake
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/