1 files changed, 16 insertions, 6 deletions

diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4
index 6e6c905143a1..10957bee7f64 100644
--- a/Documentation/i2c/busses/i2c-piix4
+++ b/Documentation/i2c/busses/i2c-piix4
@@ -23,8 +23,6 @@ Module Parameters
   Forcibly enable the PIIX4. DANGEROUS!
 * force_addr: int
   Forcibly enable the PIIX4 at the given address. EXTREMELY DANGEROUS!
-* fix_hstcfg: int
-  Fix config register. Needed on some boards (Force CPCI735).
 
 
 Description
@@ -68,7 +66,19 @@ this driver on those mainboards.
 The ServerWorks Southbridges, the Intel 440MX, and the Victory766 are
 identical to the PIIX4 in I2C/SMBus support.
 
-A few OSB4 southbridges are known to be misconfigured by the BIOS. In this
-case, you have you use the fix_hstcfg module parameter. Do not use it
-unless you know you have to, because in some cases it also breaks
-configuration on southbridges that don't need it.
+If you own Force CPCI735 motherboard or other OSB4 based systems you may need
+to change the SMBus Interrupt Select register so the SMBus controller uses
+the SMI mode.
+
+1) Use lspci command and locate the PCI device with the SMBus controller:
+   00:0f.0 ISA bridge: ServerWorks OSB4 South Bridge (rev 4f)
+   The line may vary for different chipsets. Please consult the driver source
+   for all possible PCI ids (and lspci -n to match them). Lets assume the
+   device is located at 00:0f.0.
+2) Now you just need to change the value in 0xD2 register. Get it first with
+   command: lspci -xxx -s 00:0f.0
+   If the value is 0x3 then you need to change it to 0x1
+   setpci  -s 00:0f.0 d2.b=1
+
+Please note that you don't need to do that in all cases, just when the SMBus is
+not working properly.