From 49e08c434dc1b0a608496f0187c18d2ce83a59e0 Mon Sep 17 00:00:00 2001
From: Timothy Pearson <tpearson@raptorengineeringinc.com>
Date: Fri, 28 Aug 2015 15:31:31 -0500
Subject: [PATCH 121/143] southbridge/amd/sb700: Fix drifting system clock

Change-Id: I1698c9b9b1840d254115821f3c0e76b7211e9056
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
---
 src/southbridge/amd/sb700/early_setup.c |   14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/southbridge/amd/sb700/early_setup.c b/src/southbridge/amd/sb700/early_setup.c
index da03961..fe8824f 100644
--- a/src/southbridge/amd/sb700/early_setup.c
+++ b/src/southbridge/amd/sb700/early_setup.c
@@ -431,10 +431,10 @@ static void sb700_devices_por_init(void)
 
 	/* Configure HPET Counter CLK period */
 	byte = pci_read_config8(dev, 0x43);
-	byte &= 0xF7;	/* unhide HPET regs */
+	byte &= 0xF7;				/* Unhide HPET regs */
 	pci_write_config8(dev, 0x43, byte);
-	pci_write_config32(dev, 0x34, 0x0429B17E ); /* Counter CLK period */
-	byte |= 0x08;	/* hide HPET regs */
+	pci_write_config32(dev, 0x34, 0xb0);	/* HPET_CNTRL = 0xb0 */
+	byte |= 0x08;				/* Hide HPET regs */
 	pci_write_config8(dev, 0x43, byte);
 
 	/* Features Enable */
@@ -669,6 +669,14 @@ static void sb700_pmio_por_init(void)
 	byte = pmio_read(0xbb);
 	byte |= 0xc0;
 	pmio_write(0xbb, byte);
+
+#if CONFIG_SOUTHBRIDGE_AMD_SUBTYPE_SP5100
+	/* Work around system clock drift issues */
+	byte = pmio_read(0xd4);
+	byte |= 0x1 << 6;	/* Enable alternate 14MHz clock source */
+	byte |= 0x1 << 7;	/* Disable 25MHz oscillator buffer */
+	pmio_write(0xd4, byte);
+#endif
 }
 
 /*
-- 
1.7.9.5

