Restore hardware monitoring logical device status on resume

After a suspend/resume cycle it is not guaranteed that the hardware monitoring
device is still enabled. Ensure that this is the case after resume.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/nct6775.c b/nct6775.c
index 3272356015af5478fda2d31588cb2056c05156cf..0e8105087f537d9a76864cad5547125e663e9ef0 100644 (file)
--- a/nct6775.c
+++ b/nct6775.c
@@ -890,6 +890,7 @@ struct nct6775_data {
        u8 vbat;
        u8 fandiv1;
        u8 fandiv2;
+       u8 sio_enable;
 #endif
 };
 
@@ -3218,6 +3219,8 @@ nct6775_check_fan_inputs(struct nct6775_data *data)
                superio_select(sioreg, NCT6775_LD_HWM);
                regval = superio_inb(sioreg, SIO_REG_ENABLE);
 
+               data->sio_enable = regval;
+
                if (regval & 0x80)
                        fan3pin = gpok;
                else
@@ -4050,19 +4053,26 @@ static int nct6775_suspend(struct device *dev)
 static int nct6775_resume(struct device *dev)
 {
        struct nct6775_data *data = dev_get_drvdata(dev);
+       int sioreg = data->sioreg;
        int i, j, err = 0;
+       u8 reg;
 
        mutex_lock(&data->update_lock);
        data->bank = 0xff;              /* Force initial bank selection */
 
-       if (data->kind == nct6791 || data->kind == nct6792) {
-               err = superio_enter(data->sioreg);
-               if (err)
-                       goto abort;
+       err = superio_enter(sioreg);
+       if (err)
+               goto abort;
 
-               nct6791_enable_io_mapping(data->sioreg);
-               superio_exit(data->sioreg);
-       }
+       superio_select(sioreg, NCT6775_LD_HWM);
+       reg = superio_inb(sioreg, SIO_REG_ENABLE);
+       if (reg != data->sio_enable)
+               superio_outb(sioreg, SIO_REG_ENABLE, data->sio_enable);
+
+       if (data->kind == nct6791 || data->kind == nct6792)
+               nct6791_enable_io_mapping(sioreg);
+
+       superio_exit(sioreg);
 
        /* Restore limits */
        for (i = 0; i < data->in_num; i++) {