Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Browse files

Update README with module options

  • Loading branch information...
1 parent 5e297c2 commit 031bcfe8a62f2eae755993dd809291330bc40e59 @Lekensteyn Lekensteyn committed
Showing with 33 additions and 0 deletions.
  1. +33 −0
@@ -68,6 +68,39 @@ Do **not** attempt to load a driver while the card is off or the card won't be
usable until the PCI configuration space has been recovered (for example, after
writing the contents manually or rebooting).
+### Module options
+The module has some options that control the behavior on loading and unloading:
+`load_state` and `unload_state`. Valid values are `-1`, `0` and `1` meaning "do
+not change the card state", "turn the card off" and "turn the card on"
+respectively. For example, if you want to have `bbswitch` disable the card
+immediately when loading the module while disabling the card on unload, load the
+module with:
+ # modprobe bbswitch load_state=0 unload_state=1
+The `unload_state` value can be changed on runtime, the above command yields the
+same behavior as:
+ # modprobe bbswitch load_state=0
+ # echo 1 | tee /sys/module/bbswitch/parameters/unload_state
+If not explictly set, the default behavior is not to change the power state of
+the discrete video card which equals to `load_state=-1 unload_state=-1`.
+### Disable card on boot
+These options can be useful to disable the card on boot time. Depending on your
+distribution, `/etc/modules`, `/etc/modules.conf` or some other file can be used
+to load modules on boot time. Adding the below line to the file makes the card
+get disabled on boot:
+ bbswitch load_state=0
+You have to update your initial ramdisk (initrd) for the changes propagate to
+the boot process. On Debian and Ubuntu, this can performed by running
+`update-initramfs -u` as root.
Reporting bugs

1 comment on commit 031bcfe


Nice, so that when starting bumblebee daemon, we should modprobe it like this "modprobe bbswitch load_state=0 unload_state=1". And stopping bumblebee daemon should unload bbswitch.

Please sign in to comment.
Something went wrong with that request. Please try again.