Re: [PATCH v2] igb: Fix extts capture value format for 82580/i354/i350

[Tony Nguyen]

On 6/1/2023 10:05 AM, Keller, Jacob E wrote:
> > -----Original Message-----
> > From: Yuezhen Luan <eggcar.luan@xxxxxxxxx>
> > Sent: Thursday, June 1, 2023 12:01 AM
> > To: Brandeburg, Jesse <jesse.brandeburg@xxxxxxxxx>; Nguyen, Anthony L
> > <anthony.l.nguyen@xxxxxxxxx>; davem@xxxxxxxxxxxxx;
> > edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx
> > Cc: intel-wired-lan@xxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; Keller, Jacob E <jacob.e.keller@xxxxxxxxx>; Yuezhen
> > Luan <eggcar.luan@xxxxxxxxx>
> > Subject: [PATCH v2] igb: Fix extts capture value format for 82580/i354/i350
> >
> > 82580/i354/i350 features circle-counter-like timestamp registers
> > that are different with newer i210. The EXTTS capture value in
> > AUXTSMPx should be converted from raw circle counter value to
> > timestamp value in resolution of 1 nanosec by the driver.
> >
> > This issue can be reproduced on i350 nics, connecting an 1PPS
> > signal to a SDP pin, and run 'ts2phc' command to read external
> > 1PPS timestamp value. On i210 this works fine, but on i350 the
> > extts is not correctly converted.
> >
> > The i350/i354/82580's SYSTIM and other timestamp registers are
> > 40bit counters, presenting time range of 2^40 ns, that means these
> > registers overflows every about 1099s. This causes all these regs
> > can't be used directly in contrast to the newer i210/i211s.
> >
> > The igb driver needs to convert these raw register values to
> > valid time stamp format by using kernel timecounter apis for i350s
> > families. Here the igb_extts() just forgot to do the convert.
> >
> > Signed-off-by: Yuezhen Luan <eggcar.luan@xxxxxxxxx>
>
> Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>	

Thanks for reviewing Jake.

> Thanks for fixing this!
>
> @Nguyen, Anthony L
> I think this is a worthy net fix.

Hi Yuezhen,

Could you include a Fixes: so that we can route this through net.

You should also add a target tree for your patch (net or net-next).
Here's some useful intro information for netdev [1].

Thanks,
Tony

[1] 
https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html#netdev-faq