From 905507c3790829e8a6352d857bbad446e6c1c4e6 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Fri, 28 Aug 2015 15:31:31 -0500 Subject: [PATCH] southbridge/amd/sb700: Fix drifting system clock Change-Id: I1698c9b9b1840d254115821f3c0e76b7211e9056 Signed-off-by: Timothy Pearson Reviewed-on: https://review.coreboot.org/12052 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth --- 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 f109896ea3..f7e91207f5 100644 --- a/src/southbridge/amd/sb700/early_setup.c +++ b/src/southbridge/amd/sb700/early_setup.c @@ -427,10 +427,10 @@ 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, 0x0429b17e); /* Counter CLK period */ + byte |= 0x08; /* Hide HPET regs */ pci_write_config8(dev, 0x43, byte); /* Features Enable */ @@ -661,6 +661,14 @@ 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 } /*