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From: "Rebecca Cran" <quic_rcran@quicinc.com>
To: <devel@edk2.groups.io>, Pierre Gondois <pierre.gondois@arm.com>,
	"Ard Biesheuvel" <ardb+tianocore@kernel.org>,
	Sami Mujawar <sami.mujawar@arm.com>,
	Thomas Abraham <thomas.abraham@arm.com>
Cc: Rebecca Cran <rebecca@quicinc.com>
Subject: [PATCH edk2-platforms v2 1/2] Platform/ARM/JunoPkg: Switch to MdeModulePkg/Universal/Metronome driver
Date: Mon, 20 Feb 2023 18:02:41 -0700	[thread overview]
Message-ID: <20230221010242.1038521-2-rebecca@quicinc.com> (raw)
In-Reply-To: <20230221010242.1038521-1-rebecca@quicinc.com>

The MetronomeDxe driver uses the PCD PcdMetronomeTickPeriod to calculate
how many ticks to wait in MicroSecondDelay. Given that the timer clock
on Juno runs at 50 MHz, it ticks every 20 ns; therefore, a setting of
1000 is wrong: for example it causes a call to gBS->Stall (1) to take
10 us.

The driver in MdeModulePkg/Universal/Metronome assumes the clock ticks
at least every 100 ns, which is the minimum allowed by the Metronome
protocol. Since that's the case on Juno, switch from
EmbeddedPkg/MetronomeDxe to MdeModulePkg/Universal/Metronome.

Signed-off-by: Rebecca Cran <rebecca@quicinc.com>
---
 Platform/ARM/JunoPkg/ArmJuno.dsc | 3 +--
 Platform/ARM/JunoPkg/ArmJuno.fdf | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/Platform/ARM/JunoPkg/ArmJuno.dsc b/Platform/ARM/JunoPkg/ArmJuno.dsc
index a00b866c5e9a..9cde4c862651 100644
--- a/Platform/ARM/JunoPkg/ArmJuno.dsc
+++ b/Platform/ARM/JunoPkg/ArmJuno.dsc
@@ -189,7 +189,6 @@
   # ARM Architectural Timer Frequency
   #
   gArmTokenSpaceGuid.PcdArmArchTimerFreqInHz|50000000
-  gEmbeddedTokenSpaceGuid.PcdMetronomeTickPeriod|1000
 
   gEfiMdeModulePkgTokenSpaceGuid.PcdResetOnMemoryTypeInformationChange|FALSE
 
@@ -248,10 +247,10 @@
   MdeModulePkg/Core/RuntimeDxe/RuntimeDxe.inf
   MdeModulePkg/Universal/SecurityStubDxe/SecurityStubDxe.inf
   MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleRuntimeDxe.inf
+  MdeModulePkg/Universal/Metronome/Metronome.inf
   MdeModulePkg/Universal/MonotonicCounterRuntimeDxe/MonotonicCounterRuntimeDxe.inf
   MdeModulePkg/Universal/ResetSystemRuntimeDxe/ResetSystemRuntimeDxe.inf
   EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClockRuntimeDxe.inf
-  EmbeddedPkg/MetronomeDxe/MetronomeDxe.inf
 
   MdeModulePkg/Universal/Console/ConPlatformDxe/ConPlatformDxe.inf
   MdeModulePkg/Universal/Console/ConSplitterDxe/ConSplitterDxe.inf
diff --git a/Platform/ARM/JunoPkg/ArmJuno.fdf b/Platform/ARM/JunoPkg/ArmJuno.fdf
index fca5a78cee6c..836d3cde8781 100644
--- a/Platform/ARM/JunoPkg/ArmJuno.fdf
+++ b/Platform/ARM/JunoPkg/ArmJuno.fdf
@@ -96,10 +96,10 @@ FvNameGuid         = B73FE497-B92E-416e-8326-45AD0D270092
   INF MdeModulePkg/Core/RuntimeDxe/RuntimeDxe.inf
   INF MdeModulePkg/Universal/SecurityStubDxe/SecurityStubDxe.inf
   INF MdeModulePkg/Universal/CapsuleRuntimeDxe/CapsuleRuntimeDxe.inf
+  INF MdeModulePkg/Universal/Metronome/Metronome.inf
   INF MdeModulePkg/Universal/MonotonicCounterRuntimeDxe/MonotonicCounterRuntimeDxe.inf
   INF MdeModulePkg/Universal/ResetSystemRuntimeDxe/ResetSystemRuntimeDxe.inf
   INF EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClockRuntimeDxe.inf
-  INF EmbeddedPkg/MetronomeDxe/MetronomeDxe.inf
 
   INF MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
   INF MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.inf
-- 
2.30.2


  reply	other threads:[~2023-02-21  1:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-21  1:02 [PATCH edk2-platforms v2 0/2] Platform/ARM/JunoPkg: Timer fixes Rebecca Cran
2023-02-21  1:02 ` Rebecca Cran [this message]
2023-02-21  8:44   ` [PATCH edk2-platforms v2 1/2] Platform/ARM/JunoPkg: Switch to MdeModulePkg/Universal/Metronome driver Ard Biesheuvel
2023-02-21  1:02 ` [PATCH edk2-platforms v2 2/2] Platform/ARM/JunoPkg: Set PcdArmArchTimerFreqInHz to 0 to read from CNTFRQ_EL0 Rebecca Cran
2023-02-21  8:49 ` [PATCH edk2-platforms v2 0/2] Platform/ARM/JunoPkg: Timer fixes Ard Biesheuvel

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