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@xxxxxxx>
Tested-by: Jason Andryuk <jandryuk@xxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Changes since v1:
* Added proper subject and description.
* Removed debug print.
* Added a comment.
* Added stable tag.
drivers/i2c/busses/i2c-i801.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- linux-4.16.orig/drivers/i2c/busses/i2c-i801.c 2018-04-11 17:52:34.340485371 +0200
+++ linux-4.16/drivers/i2c/busses/i2c-i801.c 2018-04-11 17:52:37.501523189 +0200
@@ -1701,6 +1701,15 @@ static void i801_remove(struct pci_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,
},
--
Jean Delvare
SUSE L3 Support
