[PATCH v3 02/10] i2c: i801: store and restore the SLVCMD register at load and unload

From: Benjamin Tissoires
Date: Wed Sep 28 2016 - 04:16:22 EST


Also do not override any other configuration in this register.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

---

no changes in v3

new in v2
---
drivers/i2c/busses/i2c-i801.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index b494a85..7334831 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -240,6 +240,7 @@ struct i801_priv {
struct i2c_adapter adapter;
unsigned long smba;
unsigned char original_hstcfg;
+ unsigned char original_slvcmd;
struct pci_dev *pci_dev;
unsigned int features;

@@ -952,7 +953,12 @@ static int i801_enable_host_notify(struct i2c_adapter *adapter)
if (!priv->host_notify)
return -ENOMEM;

- outb_p(SMBSLVCMD_HST_NTFY_INTREN, SMBSLVCMD(priv));
+ priv->original_slvcmd = inb_p(SMBSLVCMD(priv));
+
+ if (!(SMBSLVCMD_HST_NTFY_INTREN & priv->original_slvcmd))
+ outb_p(SMBSLVCMD_HST_NTFY_INTREN | priv->original_slvcmd,
+ SMBSLVCMD(priv));
+
/* clear Host Notify bit to allow a new notification */
outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv));

@@ -961,12 +967,11 @@ static int i801_enable_host_notify(struct i2c_adapter *adapter)

static void i801_disable_host_notify(struct i801_priv *priv)
{
-
if (!(priv->features & FEATURE_HOST_NOTIFY))
return;

/* disable Host Notify... */
- outb_p(0, SMBSLVCMD(priv));
+ outb_p(priv->original_slvcmd, SMBSLVCMD(priv));
/* ...and process the already queued notifications */
i2c_cancel_smbus_host_notify(priv->host_notify);
}
--
2.7.4