Debugging

suspend

no_console_suspend=1

This will force the console not to suspend. Boot with this option, chvt 1 (to console #1), and suspend using pm-suspend

Slowing down kernel messages on boot

CONFIG_BOOT_PRINTK_DELAY=y

kernel boot parameter:

boot_delay=N

where N = msecs delay between each console message.

unsorted

dmesg > dmesg_before; echo mem > /sys/power/state; dmesg > dmesg_after

Enable CONFIG_PM_DEBUG in kernel configuration, so that we can use /sys/power/pm_test.

Run: echo core/processors/devices > /sys/power/pm_test

Run: dmesg > dmesg_before; echo mem > /sys/power/state; dmesg > dmesg_after

Wait for about five seconds and see whether it can be resumed correctly.

If it can't be resumed correctly, it may be graphics driver bug. This information is helpful to narrow down the issue.