On Mon, 18 Jun 2007 16:23:53 +0100, Simon Farnsworth wrote:
> Simon Farnsworth wrote:
> > sensors output:
> >
> > # sensors
> > smsc47b397-isa-0480
> > Adapter: ISA adapter
> > temp1: +44?C
> > temp2: +53?C
> > temp3: +26?C
> > temp4: -128?C
> > fan1: 2011 RPM
> > fan2: 82 RPM
> > fan3: 1262 RPM
> > fan4: 1095 RPM
> (...)
>
> I've now experimented with cpuburn and stopping fans. It looks like 82
> RPM is the lowest speed this chip reports, as stopping a fan briefly
> caused it to report 82 RPM.
Correct, and I consider it a bug in the driver. A stopped or missing
fan should really be reported as 0 RPM, not 82. Here's a patch fixing
it.
* * * * *
Also protects ourselves against a possible division by zero.
Signed-off-by: Jean Delvare <khali at linux-fr.org>
---
drivers/hwmon/smsc47b397.c | 2 ++
1 file changed, 2 insertions(+)
--- linux-2.6.22-rc5.orig/drivers/hwmon/smsc47b397.c 2007-05-13 10:01:15.000000000 +0200
+++ linux-2.6.22-rc5/drivers/hwmon/smsc47b397.c 2007-06-23 14:53:09.000000000 +0200
@@ -174,6 +174,8 @@ static SENSOR_DEVICE_ATTR(temp4_input, S
REG: count of 90kHz pulses / revolution */
static int fan_from_reg(u16 reg)
{
+ if (reg == 0 || reg == 0xffff)
+ return 0;
return 90000 * 60 / reg;
}
--
Jean Delvare
