[flashrom] [PATCH] VIA: disable byte merging

[Michael Karcher]

All mentioned north bridges have been checked against data sheet. That's
all north bridges google found a datasheet for with "byte enable" included.

Signed-off-by: Michael Karcher <flashrom at mkarcher.dialup.fu-berlin.de>
---
 chipset_enable.c |   34 ++++++++++++++++++++++++++++++++++
 1 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/chipset_enable.c b/chipset_enable.c
index fc60484..6ef1f8d 100644
--- a/chipset_enable.c
+++ b/chipset_enable.c
@@ -639,6 +639,32 @@ static int enable_flash_ich10(struct pci_dev *dev, const char *name)
 	return enable_flash_ich_dc_spi(dev, name, 10);
 }
 
+static void via_do_byte_merge(void * arg)
+{
+	struct pci_dev * dev = arg;
+	uint8_t val;
+
+	printf_debug("Re-enabling byte merging\n");
+	val = pci_read_byte(dev, 0x71);
+	val |= 0x40;
+	pci_write_byte(dev, 0x71, val);
+}
+
+static int via_no_byte_merge(struct pci_dev *dev, const char *name)
+{
+	uint8_t val;
+
+	val = pci_read_byte(dev, 0x71);
+	if (val & 0x40)
+	{
+		printf_debug("Disabling byte merging\n");
+		val &= ~0x40;
+		pci_write_byte(dev, 0x71, val);
+		register_shutdown(via_do_byte_merge, dev);
+	}
+	return 0;
+}
+
 static int enable_flash_vt823x(struct pci_dev *dev, const char *name)
 {
 	uint8_t val;
@@ -1405,6 +1431,14 @@ const struct penable chipset_enables[] = {
 	{0x1039, 0x0746, NT, "SiS", "746",		enable_flash_sis540},
 	{0x1039, 0x0748, NT, "SiS", "748",		enable_flash_sis540},
 	{0x1039, 0x0755, NT, "SiS", "755",		enable_flash_sis540},
+	/* VIA northbridges */
+	{0x1106, 0x0585, NT, "VIA", "VT82C585VPX",	via_no_byte_merge},
+	{0x1106, 0x0595, NT, "VIA", "VT82C595",		via_no_byte_merge},
+	{0x1106, 0x0597, NT, "VIA", "VT82C597",		via_no_byte_merge},
+	{0x1106, 0x0691, NT, "VIA", "VT82C69x",		via_no_byte_merge}, /* 691, 693a, 694t, 694x checked */
+	{0x1106, 0x0601, NT, "VIA", "VT8601/VT8601A",	via_no_byte_merge},
+	{0x1106, 0x8601, NT, "VIA", "VT8601T",		via_no_byte_merge},
+	/* VIA southbridges */
 	{0x1106, 0x8324, OK, "VIA", "CX700",		enable_flash_vt823x},
 	{0x1106, 0x8231, NT, "VIA", "VT8231",		enable_flash_vt823x},
 	{0x1106, 0x3074, NT, "VIA", "VT8233",		enable_flash_vt823x},
-- 
1.7.1