System info#

• Machine: Lenovo W540 with NVIDIA K2100
• OS: Archlinux with kernel 4.18.1
• bbswitch version: 0.8-117

The following were my settings at the time when this issue happened. Kernel module bbswitch was set to be automatically loaded:

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$ cat /etc/modules-load.d/bbswitch.conf
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bbswitch

NVIDIA modules were put into the blacklist:

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$ cat /etc/modprobe.d/blacklist.conf
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blacklist nvidia
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blacklist nvidia_drm
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blacklist nvidia_modeset
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install nvidia /bin/false

bbswitch was set to turn off the GPU right after boot:

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$ cat /etc/modprobe.d/bbswitch.conf
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options bbswitch load_state=0 unload_state=1

Symptom#

# tee /proc/acpi/bbswitch <<<OFF and # tee /proc/acpi/bbswitch <<<ON wouldn’t actually change the value in /proc/acpi/bbswitch. From the output of lspci -nk or lsmod | grep nvidia, it seems that after boot bbswitch was indeed loaded and NVIDIA modules were not. The GPU, however, was always on after boot. In other words, manually switching ON/OFF and automatically turning off the GPU were not working.

Solution#

Add the following kernel parameters at boot:

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acpi_osi="!Windows 2013" acpi_osi=Linux

For more details, please refer to this discussion.

Reference#

1. Issue #592 @ Bumblebee