Re: therm_pm72 units, interface

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:

quoted

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)