Re: Enquiry on GetTimerPeriod function in Ping.c

["Carsey, Jaben" <jaben.carsey@intel.com>]

Correct 0 is supposed to indicate an error.

That function may be incorrect for your platform. I think that function is used to help determine the granularity to use when determine how long it took for packets to make their trip over the network and back.

-Jaben

> -----Original Message-----
> From: Ooi, Tzy Way
> Sent: Thursday, March 21, 2019 5:20 AM
> To: Carsey, Jaben <jaben.carsey@intel.com>; Ni, Ray <ray.ni@intel.com>;
> edk2-devel@lists.01.org
> Cc: Loh, Tien Hock <tien.hock.loh@intel.com>; Ooi, Tzy Way
> <tzy.way.ooi@intel.com>
> Subject: Enquiry on GetTimerPeriod function in Ping.c
> 
> Hi,
> 
> I am enabling an UEFI ethernet driver in our platform. While I tried to
> test the driver with ping command, I noticed that ping operation is
> aborted due to the GetTimerPeriod function return a value 0.
> 
> In the function GetTimerPeriod in ping.c, the function will return the
> value of StallCounter/RttTimerTick once it completed all the
> operations. However, the value return in my platform is zero due to
> StallCounter is having smaller value than RttTimerTick.
> 
> I am not sure what is the usage of GetTimerPeriod function and how it
> works. The GetTimerPeriod function will return 0 if any of the
> operation having an error during the execution. However, I suspect that
> this function should not return 0 when StallCounter is having less
> value than RttTimerTick? This is because the function actually did not
> encounter any error. Please correct me if I m wrong.
> 
> Thank you
> 
> Best regards,
> Tzy Way