> On Jun 5, 2015, at 4:13 PM, Saiprasad Chavali <s...@marvell.com> wrote: > > Hi Andrew, > > The “GetPerformanceCounter” is not working the way we want, the elapsed time > varies, often from incremental value to decremented value. > > For example: I save the start time with a call to the API and periodically I > call the API for End time. Measure the difference, with a time out value. It > fails > > Observation, with repeated calls to “GetPerformancecounter” the value > returned, varies from high value to low than the saved Start Time. I don’t > think this will work for us. > > We need a value that increments in time like a system time call in windows > “getsystemtime” in msecs. > > Please suggest. >
You need the correct TimerLib for your hardware. What TimerLib are you using? Thanks, Andrew Fish > Thanks > Sai > > From: Saiprasad Chavali > Sent: Wednesday, June 03, 2015 9:49 PM > To: edk2-devel@lists.sourceforge.net > Subject: RE: [edk2] getsystemtime-- help > > Thanks Andrew, will try with “GetPerformanceCounter” and see how this works > out. > The test bed at present is x86 > > Sai > > From: Andrew Fish [mailto:af...@apple.com <mailto:af...@apple.com>] > Sent: Wednesday, June 03, 2015 9:28 PM > To: edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> > Subject: Re: [edk2] getsystemtime-- help > > > On Jun 3, 2015, at 9:22 PM, Saiprasad Chavali <s...@marvell.com > <mailto:s...@marvell.com>> wrote: > > Hi Andrew, > > Trying to measure the elapsed time interval with a call to system time at > different levels. > > > If you are writing platform code, or you know the platform. > > https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/PerformanceLib.h > > <https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/PerformanceLib.h> > Which a lot of times is built on: > https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/TimerLib.h > > <https://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg/Include/Library/TimerLib.h> > > On a PC the PerformanceCounter is usually the TSC (CPU register) or the ACPI > Timer. > > Thanks, > > Andrew Fish > > > Thanks > Sai > > From: Andrew Fish [mailto:af...@apple.com <mailto:af...@apple.com>] > Sent: Wednesday, June 03, 2015 7:51 PM > To: edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> > Subject: Re: [edk2] getsystemtime-- help > > > On Jun 3, 2015, at 7:47 PM, Saiprasad Chavali <s...@marvell.com > <mailto:s...@marvell.com>> wrote: > > Hi Andrew, > > Thanks for the comment, is there way we can ping the RTC with the help of > architecture protocol, at higher TPL’s than Callback (or) nothing? > > > The rules are the rules. > > What are you trying to do? > > Thanks, > > Andrew Fish > > > > Sai > > From: Andrew Fish [mailto:af...@apple.com <mailto:af...@apple.com>] > Sent: Wednesday, June 03, 2015 7:40 PM > To: edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> > Subject: Re: [edk2] getsystemtime-- help > > > On Jun 3, 2015, at 7:27 PM, Saiprasad Chavali <s...@marvell.com > <mailto:s...@marvell.com>> wrote: > > HI, > > Is there a better way to obtain the system time? I tried GetTime and the call > hangs When I raise the TPL level. > > > Did you violate the TPL rules in the UEFI spec? > > UEFI 2.5 section 6.1Table 23. TPL Restrictions > Time Services <= TPL_CALLBACK > > If not it is a bug in the implementation of gRT->GetTime(). > > Thanks, > > Andrew Fish > > > > > Thanks > Sai > ------------------------------------------------------------------------------ > _______________________________________________ > edk2-devel mailing list > edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/edk2-devel > <https://lists.sourceforge.net/lists/listinfo/edk2-devel> > > ------------------------------------------------------------------------------ > _______________________________________________ > edk2-devel mailing list > edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/edk2-devel > <https://lists.sourceforge.net/lists/listinfo/edk2-devel> > > ------------------------------------------------------------------------------ > _______________________________________________ > edk2-devel mailing list > edk2-devel@lists.sourceforge.net <mailto:edk2-devel@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/edk2-devel > <https://lists.sourceforge.net/lists/listinfo/edk2-devel> > > ------------------------------------------------------------------------------ > _______________________________________________ > edk2-devel mailing list > edk2-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/edk2-devel
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