Most recent kernel where this bug did not occur: Don't Know Distribution: Debian testing Hardware Environment: Sager NP4750 (same as Clevo D470K, ODM manufactuer) - this is an AMD64 powered notebook Software Environment: Debian testing Problem Description: On this amd64 powered laptop, fan support does not appear to be functioning properly. The fan is not supposed to spin up unless the temperature gets above 40 degrees Celsius. However, the fan runs all the time. This problem doesn't exist in Windows. I should also note that I tested both ubuntu and knoppix live CDs compiled for standard 386 platform to see if that would fix the fan issue, but it didn't -- the same problem exists on both platforms. Also, the /proc/acpi/fan/ directory is empty even though acpi fan support is compiled into the kernel. Finally, I'm not sure if this is related, but when I have acpi debugging compiled into the kernel, I get the following information: acpi_thermal-0417 [72] thermal_get_trip_point: Invalid active threshold [0] Steps to reproduce: With this laptop, run the latest stock kernel with acpi either compiled into the kernel or as modules. If as modules, ensure that modules are loaded. Fan runs all the time.
Could you provide the output of acpidump and dmesg commands. Also you could check if your BIOS has OS-related settings. If present, you could try to change them to see if it helps. 'Windows' could be safer.
Created attachment 7180 [details] Output of acpidump Here is the output of acpidump that you requested.
Created attachment 7181 [details] Output of dmesg Here is the output of dmesg that you requested. Also, as for bios settings, there is nothing related to acpi or fan. The only setting that looks like it could have any relevance is an option to choose the OS. I currently have it set to "other". I'll change it to "windows" to see if it makes a difference.
This morning, I changed the OS setting in the bios from "Other" to "Win2K/WinXP" and it hasn't made a difference. Thanks.
Bryan, In your DSDT table neither active cooling device defined (it should have '_AL0' name), nor device with fan HID (hardware ID for fan is 'PNP0C0B') is present. But the active trip point is set to 70C ('_AC0'). This causes that "Invalid active threshold" message to appear. I think this is a BIOS bug. You could try to build your kernel with ACPI disabled and APM enabled to make fan change its state. Unfortunately, it appears impossible to manage the fan from the ACPI on your system.