1 files changed, 42 insertions, 5 deletions

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index fdc9ad805e35..ac9165968587 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -104,10 +104,31 @@ MODULE_PARM_DESC(force_addr,
 static int piix4_transaction(void);
 
 static unsigned short piix4_smba;
+static int srvrworks_csb5_delay;
 static struct pci_driver piix4_driver;
 static struct i2c_adapter piix4_adapter;
 
-static struct dmi_system_id __devinitdata piix4_dmi_table[] = {
+static struct dmi_system_id __devinitdata piix4_dmi_blacklist[] = {
+        {
+                .ident = "Sapphire AM2RD790",
+                .matches = {
+                        DMI_MATCH(DMI_BOARD_VENDOR, "SAPPHIRE Inc."),
+                        DMI_MATCH(DMI_BOARD_NAME, "PC-AM2RD790"),
+                },
+        },
+        {
+                .ident = "DFI Lanparty UT 790FX",
+                .matches = {
+                        DMI_MATCH(DMI_BOARD_VENDOR, "DFI Inc."),
+                        DMI_MATCH(DMI_BOARD_NAME, "LP UT 790FX"),
+                },
+        },
+        { }
+};
+
+/* The IBM entry is in a separate table because we only check it
+   on Intel-based systems */
+static struct dmi_system_id __devinitdata piix4_dmi_ibm[] = {
         {
                 .ident = "IBM",
                 .matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
@@ -122,8 +143,20 @@ static int __devinit piix4_setup(struct pci_dev *PIIX4_dev,
 
         dev_info(&PIIX4_dev->dev, "Found %s device\n", pci_name(PIIX4_dev));
 
+        if ((PIIX4_dev->vendor == PCI_VENDOR_ID_SERVERWORKS) &&
+            (PIIX4_dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5))
+                srvrworks_csb5_delay = 1;
+
+        /* On some motherboards, it was reported that accessing the SMBus
+           caused severe hardware problems */
+        if (dmi_check_system(piix4_dmi_blacklist)) {
+                dev_err(&PIIX4_dev->dev,
+                        "Accessing the SMBus on this system is unsafe!\n");
+                return -EPERM;
+        }
+
         /* Don't access SMBus on IBM systems which get corrupted eeproms */
-        if (dmi_check_system(piix4_dmi_table) &&
+        if (dmi_check_system(piix4_dmi_ibm) &&
                         PIIX4_dev->vendor == PCI_VENDOR_ID_INTEL) {
                 dev_err(&PIIX4_dev->dev, "IBM system detected; this module "
                         "may corrupt your serial eeprom! Refusing to load "
@@ -230,10 +263,14 @@ static int piix4_transaction(void)
         outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
 
         /* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
-        do {
+        if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */
+                msleep(2);
+        else
+                msleep(1);
+
+        while ((timeout++ < MAX_TIMEOUT) &&
+               ((temp = inb_p(SMBHSTSTS)) & 0x01))
                 msleep(1);
-                temp = inb_p(SMBHSTSTS);
-        } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
 
         /* If the SMBus is still busy, we give up */
         if (timeout >= MAX_TIMEOUT) {