i2c: i801: Restore configuration at shutdown

commit f7f6d915a10f7f2bce17e3b1b7d3376562395a28 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index fd167f78051ae49ff4f172517bc7407d1daed22d..ba8df2fde1b2769fe65bdf49f338625577b6ced9 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -1700,6 +1700,15 @@ 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)
 {
@@ -1729,6 +1738,7 @@ static struct pci_driver i801_driver = {
        .id_table       = i801_ids,
        .probe          = i801_probe,
        .remove         = i801_remove,
+       .shutdown       = i801_shutdown,
        .driver         = {
                .pm     = &i801_pm_ops,
        },