I have a dell xps 15 9550, from a couple of weeks when I hibernate or suspend pc,and after when I try to switch on it doesn't wake up.I have to shutdown it using power button.
Kernel version 4.4.0-36 Thanks.
At time or writing, the workaround was to downgrade your BIOS to 1.2.0
An alternative is to log in (although you don't see your login screen), and then pump up your brightness to max.
For your configuration, keep an eye on this wiki.
UPDATE (Alternative Solution for 16.04):
This also solved the problem for me on a newer version of the BIOS:
Create a script:
sudo nano /lib/systemd/system-sleep/97fixbacklight
#!/bin/sh # From patchwork.freedesktop.org/.../ # and en.community.dell.com/.../19985320 # Suspend Resume fails to restore PWM_GRANUALITY # Based on script by Tony.Jewell@Cregganna.Com INTEL_REG=/usr/bin/intel_reg ADDR="0x000c2000" SAVE_FILE=/var/lib/systemd/save_intel_reg_pwm_granuality [ -x "$INTEL_REG" ] || exit 0 case "$1" in pre) echo "$0: Saving Intel Register PWM_GRANUALITY" "$INTEL_REG" read "$ADDR" \ | (read addr value && echo "$value") \ >"$SAVE_FILE" sync ;; post) value=`cat "$SAVE_FILE" 2>/dev/null` if [ -n "$value" ] then echo "$0: Restoring Intel Register PWM_GRANUALITY $value" "$INTEL_REG" write "$ADDR" "$value" rm "$SAVE_FILE" fi ;; esac
Give it the right permissions:
sudo chmod +755 /lib/systemd/system-sleep/97fixbacklight