Re: [PATCH V2] PcAtChipsetPkg AcpiTimerLib: Clear bits [31:24] after reading by IoRead32()

["Zeng, Star" <star.zeng@intel.com>]

Follow the suggestion, the V3 patch has been just sent out, please help review that.

Thanks,
Star
-----Original Message-----
From: Kinney, Michael D 
Sent: Sunday, October 9, 2016 3:49 AM
To: Zeng, Star <star.zeng@intel.com>; edk2-devel@lists.01.org; Kinney, Michael D <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>; Yao, Jiewen <jiewen.yao@intel.com>; Gao, Liming <liming.gao@intel.com>
Subject: RE: [edk2] [PATCH V2] PcAtChipsetPkg AcpiTimerLib: Clear bits [31:24] after reading by IoRead32()

Star,

Minor change:

"Note: The implementation uses the lower 24-bits of the ACPI timer and is compatible with both 24-bit and 32-bit ACPI timers."

Mike

> -----Original Message-----
> From: Zeng, Star
> Sent: Friday, October 7, 2016 11:40 PM
> To: Kinney, Michael D <michael.d.kinney@intel.com>; 
> edk2-devel@lists.01.org
> Cc: Laszlo Ersek <lersek@redhat.com>; Yao, Jiewen 
> <jiewen.yao@intel.com>; Gao, Liming <liming.gao@intel.com>; Zeng, Star 
> <star.zeng@intel.com>
> Subject: RE: [edk2] [PATCH V2] PcAtChipsetPkg AcpiTimerLib: Clear bits 
> [31:24] after reading by IoRead32()
> 
> Mike,
> 
> Just get your point, that means the [31:24] will be always ignored 
> regardless of the ACPI timer is 24Bits or 32Bits.
> 
> How about updating the comments like below?
> 
> "Note: The implementation only uses the lower 24-bits of the ACPI 
> timer and can be compatible with both 24-bits and 32-bits ACPI timers."
> 
> 
> Thanks,
> Star
> -----Original Message-----
> From: Kinney, Michael D
> Sent: Wednesday, September 28, 2016 10:58 PM
> To: Zeng, Star <star.zeng@intel.com>; edk2-devel@lists.01.org; Kinney, 
> Michael D <michael.d.kinney@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>; Yao, Jiewen 
> <jiewen.yao@intel.com>; Gao, Liming <liming.gao@intel.com>; Zeng, Star 
> <star.zeng@intel.com>
> Subject: RE: [edk2] [PATCH V2] PcAtChipsetPkg AcpiTimerLib: Clear bits 
> [31:24] after reading by IoRead32()
> 
> Star,
> 
> I think the comment should be updated.  This updated algorithm only 
> uses the lower 24-bits of the ACPI timer.  It is compatible with both 24-bit and 32-bit ACPI timers.
> 
> Mike
> 
> > -----Original Message-----
> > From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf 
> > Of Star Zeng
> > Sent: Wednesday, September 28, 2016 5:49 AM
> > To: edk2-devel@lists.01.org
> > Cc: Laszlo Ersek <lersek@redhat.com>; Yao, Jiewen 
> > <jiewen.yao@intel.com>; Gao, Liming <liming.gao@intel.com>; Zeng, 
> > Star <star.zeng@intel.com>
> > Subject: [edk2] [PATCH V2] PcAtChipsetPkg AcpiTimerLib: Clear bits 
> > [31:24] after reading by IoRead32()
> >
> > From: "Zeng, Star" <star.zeng@intel.com>
> >
> > Clear bits [31:24] when reading ACPI timer count by IoRead32(), also 
> > add comments "Note: The library only supports 24Bits ACPI timer" in INF.
> >
> > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > Cc: Liming Gao <liming.gao@intel.com>
> > Cc: Laszlo Ersek <lersek@redhat.com>
> > Contributed-under: TianoCore Contribution Agreement 1.0
> > Signed-off-by: Star Zeng <star.zeng@intel.com>
> > ---
> >  PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c       | 8 ++++----
> >  PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf | 6 ++++-- 
> > PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf  | 8 
> > +++++---
> >  3 files changed, 13 insertions(+), 9 deletions(-)
> >
> > diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c
> > b/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c
> > index 020031e3f4a5..792781a33f3f 100644
> > --- a/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c
> > +++ b/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c
> > @@ -162,14 +162,14 @@ InternalAcpiDelay (
> >      //
> >      // The target timer count is calculated here
> >      //
> > -    Ticks = IoRead32 (Port) + Delay;
> > +    Ticks = IoBitFieldRead32 (Port, 0, 23) + Delay;
> >      Delay = BIT22;
> >      //
> >      // Wait until time out
> >      // Delay >= 2^23 could not be handled by this function
> >      // Timer wrap-arounds are handled correctly by this function
> >      //
> > -    while (((Ticks - IoRead32 (Port)) & BIT23) == 0) {
> > +    while (((Ticks - IoBitFieldRead32 (Port, 0, 23)) & BIT23) == 0) 
> > + {
> >        CpuPause ();
> >      }
> >    } while (Times-- > 0);
> > @@ -371,7 +371,7 @@ InternalCalculateTscFrequency (
> >    // Use 363 * 9861 = 3579543 Hz which is within 2 Hz of ACPI_TIMER_FREQUENCY.
> >    // 363 counts is a calibration time of 101.4 uS.
> >    //
> > -  Ticks = IoRead32 (TimerAddr) + 363;
> > +  Ticks = IoBitFieldRead32 (TimerAddr, 0, 23) + 363;
> >
> >    StartTSC = AsmReadTsc ();                                         // Get base
> value
> > for the TSC
> >    //
> > @@ -380,7 +380,7 @@ InternalCalculateTscFrequency (
> >    // When the current ACPI timer value is greater than 'Ticks',
> >    // the while loop will exit.
> >    //
> > -  while (((Ticks - IoRead32 (TimerAddr)) & BIT23) == 0) {
> > +  while (((Ticks - IoBitFieldRead32 (TimerAddr, 0, 23)) & BIT23) ==
> > + 0) {
> >      CpuPause();
> >    }
> >    EndTSC = AsmReadTsc ();                                           // TSC value
> 101.4
> > us later
> > diff --git 
> > a/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
> > b/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
> > index 48caebff1354..913fbfe7d30e 100644
> > --- a/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
> > +++ b/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
> > @@ -2,9 +2,11 @@
> >  #  Base ACPI Timer Library
> >  #
> >  #  Provides basic timer support using the ACPI timer hardware.  The 
> > performance -#  counter features are provided by the processors time stamp counter.
> > +#  counter features are provided by the processors time stamp counter.
> >  #
> > -#  Copyright (c) 2013 - 2015, Intel Corporation. All rights 
> > reserved.<BR>
> > +#  Note: The library only supports 24Bits ACPI timer.
> > +#
> > +#  Copyright (c) 2013 - 2016, Intel Corporation. All rights 
> > +reserved.<BR>
> >  #  This program and the accompanying materials  #  are licensed and 
> > made available under the terms and conditions of the BSD License  # 
> > which accompanies this distribution.  The full text of the license 
> > may be found at diff --git 
> > a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
> > b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
> > index 3446c03eda21..33d4970afc57 100644
> > --- a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
> > +++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
> > @@ -2,9 +2,11 @@
> >  #  DXE ACPI Timer Library
> >  #
> >  #  Provides basic timer support using the ACPI timer hardware.  The 
> > performance -#  counter features are provided by the processors time stamp counter.
> > +#  counter features are provided by the processors time stamp counter.
> >  #
> > -#  Copyright (c) 2013 - 2015, Intel Corporation. All rights 
> > reserved.<BR>
> > +#  Note: The library only supports 24Bits ACPI timer.
> > +#
> > +#  Copyright (c) 2013 - 2016, Intel Corporation. All rights 
> > +reserved.<BR>
> >  #  This program and the accompanying materials  #  are licensed and 
> > made available under the terms and conditions of the BSD License  # 
> > which accompanies this distribution.  The full text of the license 
> > may be found at @@ -49,4 +51,4 @@ [Pcd]
> >    gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPciBarRegisterOffset     ## CONSUMES
> >    gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPortBaseAddress          ## CONSUMES
> >    gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiPm1TmrOffset               ## CONSUMES
> > -  gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPortBaseAddressMask      ## CONSUMES
> > \ No newline at end of file
> > +  gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPortBaseAddressMask      ## CONSUMES
> > --
> > 2.8.1.windows.1
> >
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