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Diffstat (limited to 'drivers/i2c/busses/i2c-i801.c')
-rw-r--r--drivers/i2c/busses/i2c-i801.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 08847e8b8998..eb3627f35d12 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -146,6 +146,7 @@
#define SMBHSTCFG_HST_EN 1
#define SMBHSTCFG_SMB_SMI_EN 2
#define SMBHSTCFG_I2C_EN 4
+#define SMBHSTCFG_SPD_WD 0x10
/* TCO configuration bits for TCOCTL */
#define TCOCTL_EN 0x0100
@@ -865,9 +866,16 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
block = 1;
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
- /* NB: page 240 of ICH5 datasheet shows that the R/#W
- * bit should be cleared here, even when reading */
- outb_p((addr & 0x7f) << 1, SMBHSTADD(priv));
+ /*
+ * NB: page 240 of ICH5 datasheet shows that the R/#W
+ * bit should be cleared here, even when reading.
+ * However if SPD Write Disable is set (Lynx Point and later),
+ * the read will fail if we don't set the R/#W bit.
+ */
+ outb_p(((addr & 0x7f) << 1) |
+ ((priv->original_hstcfg & SMBHSTCFG_SPD_WD) ?
+ (read_write & 0x01) : 0),
+ SMBHSTADD(priv));
if (read_write == I2C_SMBUS_READ) {
/* NB: page 240 of ICH5 datasheet also shows
* that DATA1 is the cmd field when reading */
@@ -1573,6 +1581,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
/* Disable SMBus interrupt feature if SMBus using SMI# */
priv->features &= ~FEATURE_IRQ;
}
+ if (temp & SMBHSTCFG_SPD_WD)
+ dev_info(&dev->dev, "SPD Write Disable is set\n");
/* Clear special mode bits */
if (priv->features & (FEATURE_SMBUS_PEC | FEATURE_BLOCK_BUFFER))