i2c: i801: Fix resume bug

commit 66d402e2e9455cf0213c42b97f22a0493372d7cc upstream.

On suspend the original host configuration gets restored. The
resume routine has to undo this, otherwise the SMBus master
may be left in disabled state or in i2c mode.

[JD: Rebased on v5.8, moved the write into i801_setup_hstcfg.]

Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
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 3ff6fbd79b1273fb980728e4949caf30cf980fe2..9a80c3c7e8af279e200fd77abc3632904e3471ed 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -1688,6 +1688,16 @@ static inline int i801_acpi_probe(struct i801_priv *priv) { return 0; }
 static inline void i801_acpi_remove(struct i801_priv *priv) { }
 #endif
 
+static unsigned char i801_setup_hstcfg(struct i801_priv *priv)
+{
+       unsigned char hstcfg = priv->original_hstcfg;
+
+       hstcfg &= ~SMBHSTCFG_I2C_EN;    /* SMBus timing */
+       hstcfg |= SMBHSTCFG_HST_EN;
+       pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hstcfg);
+       return hstcfg;
+}
+
 static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
        unsigned char temp;
@@ -1804,14 +1814,10 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
                return err;
        }
 
-       pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &temp);
-       priv->original_hstcfg = temp;
-       temp &= ~SMBHSTCFG_I2C_EN;      /* SMBus timing */
-       if (!(temp & SMBHSTCFG_HST_EN)) {
+       pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &priv->original_hstcfg);
+       temp = i801_setup_hstcfg(priv);
+       if (!(priv->original_hstcfg & SMBHSTCFG_HST_EN))
                dev_info(&dev->dev, "Enabling SMBus device\n");
-               temp |= SMBHSTCFG_HST_EN;
-       }
-       pci_write_config_byte(priv->pci_dev, SMBHSTCFG, temp);
 
        if (temp & SMBHSTCFG_SMB_SMI_EN) {
                dev_dbg(&dev->dev, "SMBus using interrupt SMI#\n");
@@ -1937,6 +1943,7 @@ static int i801_resume(struct device *dev)
 {
        struct i801_priv *priv = dev_get_drvdata(dev);
 
+       i801_setup_hstcfg(priv);
        i801_enable_host_notify(&priv->adapter);
 
        return 0;