echo 75000 > /sys/class/thermal/thermal_zone0/trip_point_1_temp - Permission denied!!

[Seth Forshee]

On Thu, Jun 05, 2014 at 10:39:46AM -0400, John Hupp wrote:
> Trying to edit an acpi thermal trip point, I show from
> /sys/class/thermal/thermal_zone0:
> 
> $ echo 75000 > trip_point_1_temp
> bash: trip_point_1_temp: Permission denied

This command isn't going to work unless you're in a root shell.

> I get the same result using sudo.

Is it really the same, or does it say "Operation not permitted" instead?
If so, then it probably means that the driver behind that trip point
does not support changing the trip point temperature (which isn't
necessarily a bug, it might really be impossible to change it).

> I also tried with the same result:
> 
> $ echo 75000 | sudo tee trip_point_1_temp
> and
> $ sudo sh -c "echo 75000 > trip_point_1_temp"
> 
> I also tried "echo -n" instead of just "echo" with the same result.
> 
> I also tried echo "75000" instead of just echo 75000.
> 
> I also tried the above commands from
> /sys/devices/virtual/thermal/thermal_zone0 (where the links from
> /sys/class/thermal point), all with the same result.
> 
> These thermal attributes are supposed to be editable by the user,
> and this is confirmed by https://www.kernel.org/doc/Documentation/thermal/x86_pkg_temperature_thermal
> 
> I have read that there was one or more bugs in the past that behaved
> this way.  Do we have a new bug?
> 
> 
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