Re: [edk2-devel] [PATCH v2] UefiCpuPkg/MpInitLib DXE: Add PCD to control AP status check interval

["Laszlo Ersek" <lersek@redhat.com>]

On 03/25/20 02:24, Wu, Hao A wrote:
>> -----Original Message-----
>> From: Ni, Ray
>> Sent: Wednesday, March 25, 2020 8:46 AM
>> To: Kinney, Michael D; Zeng, Star; Wu, Hao A; devel@edk2.groups.io
>> Cc: Dong, Eric; Laszlo Ersek; Brian J . Johnson
>> Subject: RE: [edk2-devel] [PATCH v2] UefiCpuPkg/MpInitLib DXE: Add PCD to
>> control AP status check interval
>>
>> Mike, Hao,
>> I searched all edk2 code using regex pattern "Pcd.*Timeout.*", "Pcd.*Timer.*",
>> "Pcd.*Delay.*"
>> and found below PCDs:
>>
>> gEfiMdePkgTokenSpaceGuid.PcdSpinLockTimeout: in tick unit depending on the
>> TimerLib used
>> gEfiMdePkgTokenSpaceGuid.PcdUsbTransferTimeoutValue: in 1ms unit
>> gPcAtChipsetPkgTokenSpaceGuid.PcdHpetDefaultTimerPeriod: in 100ns unit
>>
>> gEfiMdeModulePkgTokenSpaceGuid.PcdSataSpinUpDelayInSecForRecoveryPat
>> h: in 1s unit
>> gUefiCpuPkgTokenSpaceGuid.PcdCpuInitIpiDelayInMicroSeconds: in 1us unit
>> gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmApSyncTimeout: in 1us unit
>> gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdUsbXhciDebugDetectTimeout: in
>> 1us unit
>>
>> 1 uses timer ticks as unit.
>> 1 uses as unit.
>> 1 uses ms as unit.
>> 3 use us as unit.
>> 1 uses 100ns as unit.
>>
>> UefiCpuPkg uses us consistently as the unit.
>> So how about using us for this PCD as well?
>> And don't forget to name the PCD as
>> "PcdCpuApStatusCheckIntervalInMicroSeconds" so developers who set the PCD
>> can be aware by reading the name.
> 
> 
> Hello Ray,
> 
> Agree with your suggestion.
> I will follow up with this approach and provide a new version of the patch.

Works for me, too.

Thanks!
Laszlo