> On Jun 5, 2015, at 4:21 PM, Andrew Fish <af...@apple.com> wrote: > > >> On Jun 5, 2015, at 4:13 PM, Saiprasad Chavali <s...@marvell.com >> <mailto: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 the ACPI Timer version of the Timer lib rolls over every 3.54 seconds. You may need a TSC version of the TimerLib to get good timing data. Thanks, Andrew Fish >> 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 >> <mailto: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 <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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