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TLP wrongly starting in battery mode #313
A recent kernel upgrade from 4.9 to 4.14 has triggered a power issue on my audio card. I've tracked the problem down to TLP correctly starting in AC mode for the 4.9 kernel and BAT mode for the 4.14. In my case
I use a desktop PC, so there is no battery. TBH I'm not even sure if my system needs TLP, it came with the default Manjaro install. However, I do use a wireless keyboard (Logitech K800) and wireless mouse (Logitech Performance MX rechargable). I'm guessing, combined with the newer kernel, TLP is detecting the state of these batteries and incorrectly thinking the system is battery powered.
Please let me know if there is any other debugging information I can provide.
obviously a regression from kernel 4.9 to 4.14. Just for the record please show power supply data:
(for 4.9 and 4.14).
I suggest you file a bug report against the kernel.
I'd try a BIOS update too.
In the meantime you may change TLP's configuration as a workaround:
(forces TLP into AC mode).
The power supply data for the 4.14 kernel:
For the 4.9 kernel, there is no output.
My BIOS is already up to date, in fact the board is an old ASUS M4A78LT-LE, a new BIOS hasn't been released in years.
Do you really think this is a kernel bug? I don't know how TLP distinguishes between AC and BAT, but if the kernel is reporting to TLP that my desktop PC is battery powered then I'll most certainly file a bug report. I came here first since TLP is changing my power settings.
I'll try your suggested config changes. I changed
I've just had a look at the get_sys_power_supply function and I think I see the problem.
Perhaps the loop could read and ignore a 'Logitech' value in the 'manufacturer' file. Or, you could read a combination of
I only discovered this problem because my speakers started making a buzzing sound with the new kernel. I'm going to guess many more people on desktop PC's are running in battery mode without even knowing it (just because a wireless battery powered device is being detected but a 'Mains' device is not).
I don't think this is a kernel regression as Bluetooth devices will also report their battery status. Instead, TLP should probably make a distinction between HID devices and internal batteries.
A selection of random but related web links: