i2c: i801: Restore configuration at shutdown

On some systems, the BIOS expects certain SMBus register values to
match the hardware defaults. Restore these configuration registers at
shutdown time to avoid confusing the BIOS. This avoids hard-locking
such systems upon reboot.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@vger.kernel.org

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 17aa20a55642d40b51d673df7f51770179672b28..e0d59e9ff3c6de53b5c94a54fbd21e88713ecd1b 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -1701,6 +1701,15 @@ static void i801_remove(struct pci_dev *dev)
         */
 }
 
+static void i801_shutdown(struct pci_dev *dev)
+{
+       struct i801_priv *priv = pci_get_drvdata(dev);
+
+       /* Restore config registers to avoid hard hang on some systems */
+       i801_disable_host_notify(priv);
+       pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
+}
+
 #ifdef CONFIG_PM
 static int i801_suspend(struct device *dev)
 {
@@ -1730,6 +1739,7 @@ static struct pci_driver i801_driver = {
        .id_table       = i801_ids,
        .probe          = i801_probe,
        .remove         = i801_remove,
+       .shutdown       = i801_shutdown,
        .driver         = {
                .pm     = &i801_pm_ops,
        },