Commit 3b0e2091 authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Wolfram Sang
Browse files

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: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: default avatarJean Delvare <jdelvare@suse.de>
Acked-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 94126645

drivers/i2c/busses/i2c-i801.c

+13 −7
Original line number Diff line number Diff line
@@ -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;

}