From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Date: Wed, 13 Sep 2017 19:42:05 +0200 > If the network interface is kept running during suspend, the net core > may call net_device_ops.ndo_start_xmit() while the Ethernet device is > still suspended, which may lead to a system crash. > > E.g. on sh73a0/kzm9g and r8a73a4/ape6evm, the external Ethernet chip is > driven by a PM controlled clock. If the Ethernet registers are accessed > while the clock is not running, the system will crash with an imprecise > external abort. > > As this is a race condition with a small time window, it is not so easy > to trigger at will. Using pm_test may increase your chances: > > # echo 0 > /sys/module/printk/parameters/console_suspend > # echo platform > /sys/power/pm_test > # echo mem > /sys/power/state > > To fix this, make sure the network interface is quietened during > suspend. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Applied.
