drm/nouveau/fan: handle the cases where we are outside of the linear zone
authorMartin Peres <martin.peres@labri.fr>
Thu, 20 Dec 2012 00:32:09 +0000 (01:32 +0100)
committerBen Skeggs <bskeggs@redhat.com>
Wed, 20 Feb 2013 06:00:33 +0000 (16:00 +1000)
This fixes a bug where, when temperature is outside of the linear range, fan
pwm would be outside of the allowed range ([0, 100]) and could get negative in
some cases.

It seems like a regression that happened when we re-worked the fan management
logic before merging.

Tested-by: Ozan Çağlayan <ozancag@gmail.com>
Signed-off-by: Martin Peres <martin.peres@labri.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
drivers/gpu/drm/nouveau/core/subdev/therm/base.c

index b35b4a249c5f215c61d69d313764e13b8dbe0a44..25b7f6a907c83ff010eb5d4e5e26e6bf97415d8a 100644 (file)
@@ -71,6 +71,13 @@ nouveau_therm_update_linear(struct nouveau_therm *therm)
        u8  temp = therm->temp_get(therm);
        u16 duty;
 
+       /* handle the non-linear part first */
+       if (temp < linear_min_temp)
+               return priv->fan->bios.min_duty;
+       else if (temp > linear_max_temp)
+               return priv->fan->bios.max_duty;
+
+       /* we are in the linear zone */
        duty  = (temp - linear_min_temp);
        duty *= (priv->fan->bios.max_duty - priv->fan->bios.min_duty);
        duty /= (linear_max_temp - linear_min_temp);