From patchwork Tue Sep  7 07:07:36 2010
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Subject: [2/4] Enable TSC calibration with timer2 by default.
Date: Tue, 07 Sep 2010 07:07:36 -0000
From: Patrick Georgi <patrick@georgi-clan.de>
X-Patchwork-Id: 1880
Message-Id: <4C85E4B8.9000203@georgi-clan.de>
To: coreboot@coreboot.org

Am 07.09.2010 01:23, schrieb Kevin O'Connor:
> 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.
How about this instead? It allows boards that require the workaround to
simply "select" it.


Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Kevin O'Connor <kevin@koconnor.net>


Index: src/cpu/x86/Kconfig
===================================================================
--- src/cpu/x86/Kconfig	(Revision 5777)
+++ src/cpu/x86/Kconfig	(Arbeitskopie)
@@ -19,7 +19,7 @@
 	bool
 	default n
 
-config TSC_X86RDTSC_CALIBRATE_WITH_TIMER2
+config TSC_CALIBRATE_WITH_IO
 	bool
 	default n
 
Index: src/cpu/x86/tsc/delay_tsc.c
===================================================================
--- src/cpu/x86/tsc/delay_tsc.c	(Revision 5777)
+++ src/cpu/x86/tsc/delay_tsc.c	(Arbeitskopie)
@@ -7,7 +7,7 @@
 
 static unsigned long clocks_per_usec;
 
-#if (CONFIG_TSC_X86RDTSC_CALIBRATE_WITH_TIMER2 == 1)
+#if !CONFIG_TSC_CALIBRATE_WITH_IO
 #define CLOCK_TICK_RATE	1193180U /* Underlying HZ */
 
 /* ------ Calibrate the TSC -------
@@ -82,7 +82,7 @@
 	return 0;
 }
 
-#else /*  CONFIG_TSC_X86RDTSC_CALIBRATE_WITH_TIMER2 */
+#else /*  CONFIG_TSC_CALIBRATE_WITH_IO */
 
 /*
  * this is the "no timer2" version.
Index: src/southbridge/amd/cs5536/Kconfig
===================================================================
--- src/southbridge/amd/cs5536/Kconfig	(Revision 5777)
+++ src/southbridge/amd/cs5536/Kconfig	(Arbeitskopie)
@@ -19,12 +19,5 @@
 
 config SOUTHBRIDGE_AMD_CS5536
 	bool
-	select TSC_X86RDTSC_CALIBRATE_WITH_TIMER2
+	select UDELAY_TSC
 
-config UDELAY_TSC
-	bool
-	default y
-	depends on SOUTHBRIDGE_AMD_CS5536
-
-
-