i2c: i801: add helper i801_restore_regs

In few places relevant registers are reset to their initial value on
driver load. Factor this out to new helper i801_restore_regs to avoid
code duplication.
Even though no actual problems are known, this patch may contribute
to avoiding potential issues by:
- restoring register values also in the error path of i2c_add_adapter
- making restoring registers the last step (especially in i801_remove)

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 9bd712eafa8e6ad050598d84aa6a89804fdab8e6..811541797b15083a8920ec172f4988c177475159 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -1629,6 +1629,12 @@ static void i801_setup_hstcfg(struct i801_priv *priv)
        pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hstcfg);
 }
 
+static void i801_restore_regs(struct i801_priv *priv)
+{
+       outb_p(priv->original_hstcnt, SMBHSTCNT(priv));
+       pci_write_config_byte(priv->pci_dev, SMBHSTCFG, priv->original_hstcfg);
+}
+
 static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
        int err, i;
@@ -1755,6 +1761,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
        if (err) {
                platform_device_unregister(priv->tco_pdev);
                i801_acpi_remove(priv);
+               i801_restore_regs(priv);
                return err;
        }
 
@@ -1779,12 +1786,10 @@ static void i801_remove(struct pci_dev *dev)
 {
        struct i801_priv *priv = pci_get_drvdata(dev);
 
-       outb_p(priv->original_hstcnt, SMBHSTCNT(priv));
        i801_disable_host_notify(priv);
        i801_del_mux(priv);
        i2c_del_adapter(&priv->adapter);
        i801_acpi_remove(priv);
-       pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
 
        platform_device_unregister(priv->tco_pdev);
 
@@ -1792,6 +1797,8 @@ static void i801_remove(struct pci_dev *dev)
        if (!priv->acpi_reserved)
                pm_runtime_get_noresume(&dev->dev);
 
+       i801_restore_regs(priv);
+
        /*
         * do not call pci_disable_device(dev) since it can cause hard hangs on
         * some systems during power-off (eg. Fujitsu-Siemens Lifebook E8010)
@@ -1802,18 +1809,17 @@ 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 */
-       outb_p(priv->original_hstcnt, SMBHSTCNT(priv));
        i801_disable_host_notify(priv);
-       pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
+       /* Restore config registers to avoid hard hang on some systems */
+       i801_restore_regs(priv);
 }
 
 static int i801_suspend(struct device *dev)
 {
        struct i801_priv *priv = dev_get_drvdata(dev);
 
-       outb_p(priv->original_hstcnt, SMBHSTCNT(priv));
-       pci_write_config_byte(priv->pci_dev, SMBHSTCFG, priv->original_hstcfg);
+       i801_restore_regs(priv);
+
        return 0;
 }