therm_pm72 units, interface

[Aaro Koskinen]

Hi,

On Sat, Jul 20, 2013 at 09:16:49AM +1000, Benjamin Herrenschmidt wrote:
> On Fri, 2013-07-19 at 20:43 +0300, Aaro Koskinen wrote:
> > I booted a Xserve today with 3.11-rc1, and noticed the noise is coming
> > from slots-fan (PCI fan?) which is always 99%, although the slots-temp is
> > just 33. Is it on purpose the rm31 slots PID params are totally different
> > from therm_pm72 slots params? It seems like they have been copied from
> > pm72 "drive bay" PID params instead.
> 
> Could be my mistake. What happens if you change them to match the old code ?

I tried the change below (use SLOTS_PID_* values from therm_pm72.h),
and the noise level is considerably lower. The slots-fan stays at 19%,
and slots-temp rises to 42'C but not higher after running couple of hours.

diff --git a/drivers/macintosh/windfarm_rm31.c b/drivers/macintosh/windfarm_rm31.c
index 0b9a79b..82fc86a 100644
--- a/drivers/macintosh/windfarm_rm31.c
+++ b/drivers/macintosh/windfarm_rm31.c
@@ -439,15 +439,15 @@ static void backside_setup_pid(void)
 
 /* Slots fan */
 static const struct wf_pid_param slots_param = {
-	.interval	= 5,
-	.history_len	= 2,
-	.gd		= 30 << 20,
-	.gp		= 5 << 20,
-	.gr		= 0,
-	.itarget	= 40 << 16,
-	.additive	= 1,
-	.min		= 300,
-	.max		= 4000,
+	.interval	= 1,
+	.history_len	= 20,
+	.gd		= 0,
+	.gp		= 0,
+	.gr		= 0x00100000,
+	.itarget	= 3200000,
+	.additive	= 0,
+	.min		= 20,
+	.max		= 100,
 };
 
 static void slots_fan_tick(void)