Lenovo Thinkpad E540

= Hardware information =

Hardware details
= Issues =

(see this link for more information). It is recommended to update your BIOS to the newest version to fix this problem.
 * If the device has an UEFI Firmware version >1.61 it will not resume from suspend

These problems seem to be fixed, but not 100% sure: There is a workaround for this problem (see section Workarounds). working
 * Sometimes, when the device resumes from suspend, the power LED will blink.
 * Sometimes, when the device resumes from suspend, the hotkeys are no longer

= Workarounds =

No Wifi after resume
When the device resumes from suspend, the Wifi will no longer work. This seems to be a problem with wpa_supplicant, because restarting it fixes it. On Ubuntu distributions, this problem does not occur, so they probably have a patch for it. See this Ubuntu bug report for more information: https://bugs.launchpad.net/ubuntu/+source/gnome-nettool/+bug/1311257.

With this script in your "/etc/pm/sleep.d" folder, you can restart wpa_supplicant after suspend:

After saving the script file, you have to make it executable:

No resume possible (UEFI problem)
When you open the lid or press a button to resume, the device will not resume. The fan seems to come on, but thats it. You have to hard reset (push the power button for about 5 seconds) to make it work again. To make resume work, you have to turn off "USB 3 Mode" in the UEFI settings (pushing Enter when the laptop starts). The drawback of this method is, of course, that your USB ports will only work in USB 2 mode, which means much slower data transfers.

Blinking power LED after resume
Sometimes, when the device resumes, the power LED will blink instead of stay lit. This can be fixed by resetting the power LED after suspend. To do this, you have to issue the following command as root:

See "Documentation/laptops/thinkpad-acpi.txt" in your kernel source directory for more information.

= Kernel =

= Required packages = Wifi and bluetooth firmware:
 * sys-firmware/linux-firmware

= Recommended packages = If you are using Xfce4, you can install this package to see the status of your modifier keys (Caps-Lock,Num-Lock): For GNOME 3 there is the "Lock keys" extension, which you can find on extensions.gnome.org
 * xfce-extra/xfce4-kbdleds-plugin

Other desktop environments have similar panel plugins.