Patchwork [2/4] Enable TSC calibration with timer2 by default.

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Submitter Kevin O'Connor
Date 2010-09-06 23:23:56
Message ID <653639f7559fcf14685c35907fd9e733c2e89901.1283815188.git.kevin@koconnor.net>
Download mbox | patch
Permalink /patch/1874/
State Superseded
Headers show

Comments

Kevin O'Connor - 2010-09-06 23:23:56
Enable TSC_X86RDTSC_CALIBRATE_WITH_TIMER2 by default.  Without this
set, almost all boards use the inb(0x80) method.  Unfortunately, that
method takes over a second to calibrate, and it's results are not as
reliable.

There is a chance that some boards may not work well with the timer2
method.  This is likely rare, because both libpayload and seabios use
the timer2 method unconditionally and there has not been reports of an
issue.  Should a board not support the more accurate timer2 mechanism,
it will need to be updated to actively disable it.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 src/cpu/x86/Kconfig |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Patch

diff --git a/src/cpu/x86/Kconfig b/src/cpu/x86/Kconfig
index 325991e..8cd999e 100644
--- a/src/cpu/x86/Kconfig
+++ b/src/cpu/x86/Kconfig
@@ -21,7 +21,7 @@  config UDELAY_TSC
 
 config TSC_X86RDTSC_CALIBRATE_WITH_TIMER2
 	bool
-	default n
+	default y
 
 config XIP_ROM_BASE
 	hex