1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c
index 460292bad74a..d18031944960 100644
--- a/drivers/hwmon/w83627ehf.c
+++ b/drivers/hwmon/w83627ehf.c
@@ -79,6 +79,10 @@ static unsigned short force_id;
 module_param(force_id, ushort, 0);
 MODULE_PARM_DESC(force_id, "Override the detected device ID");
 
+static unsigned short fan_debounce;
+module_param(fan_debounce, ushort, 0);
+MODULE_PARM_DESC(fan_debounce, "Enable debouncing for fan RPM signal");
+
 #define DRVNAME "w83627ehf"
 
 /*
@@ -187,6 +191,7 @@ static const u16 W83627EHF_REG_TEMP_CONFIG[] = { 0, 0x152, 0x252, 0 };
 /* NCT6775F has its own fan divider registers */
 #define NCT6775_REG_FANDIV1             0x506
 #define NCT6775_REG_FANDIV2             0x507
+#define NCT6775_REG_FAN_DEBOUNCE        0xf0
 
 #define W83627EHF_REG_ALARM1            0x459
 #define W83627EHF_REG_ALARM2            0x45A
@@ -2089,6 +2094,22 @@ static int __devinit w83627ehf_probe(struct platform_device *pdev)
                 fan5pin = !(superio_inb(sio_data->sioreg, 0x24) & 0x02);
                 fan4min = fan4pin;
         }
+
+        if (fan_debounce &&
+            (sio_data->kind == nct6775 || sio_data->kind == nct6776)) {
+                u8 tmp;
+
+                superio_select(sio_data->sioreg, W83627EHF_LD_HWM);
+                tmp = superio_inb(sio_data->sioreg, NCT6775_REG_FAN_DEBOUNCE);
+                if (sio_data->kind == nct6776)
+                        superio_outb(sio_data->sioreg, NCT6775_REG_FAN_DEBOUNCE,
+                                     0x3e | tmp);
+                else
+                        superio_outb(sio_data->sioreg, NCT6775_REG_FAN_DEBOUNCE,
+                                     0x1e | tmp);
+                pr_info("Enabled fan debounce for chip %s\n", data->name);
+        }
+
         superio_exit(sio_data->sioreg);
 
         /* It looks like fan4 and fan5 pins can be alternatively used