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

[Tony Nguyen <anthony.l.nguyen@intel.com>]

On 6/1/2023 10:05 AM, Keller, Jacob E wrote:
> 
> 
>> -----Original Message-----
>> From: Yuezhen Luan <eggcar.luan@gmail.com>
>> Sent: Thursday, June 1, 2023 12:01 AM
>> To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L
>> <anthony.l.nguyen@intel.com>; davem@davemloft.net;
>> edumazet@google.com; kuba@kernel.org; pabeni@redhat.com
>> Cc: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; linux-
>> kernel@vger.kernel.org; Keller, Jacob E <jacob.e.keller@intel.com>; Yuezhen
>> Luan <eggcar.luan@gmail.com>
>> 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@gmail.com>
> 
> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>	

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