From af8db1508f2c9f3b6e633e2d2d906c6557c617f9 Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Tue, 15 Nov 2011 21:52:29 +0100 Subject: [PATCH] PM / driver core: disable device's runtime PM during shutdown There may be an issue when the user issue "reboot/shutdown" command, then the device has shut down its hardware, after that, this runtime-pm featured device's driver will probably be scheduled to do its suspend routine, and at its suspend routine, it may access hardware, but the device has already shutdown physically, then the system hang may be occurred. I ran out this issue using an auto-suspend supported USB devices, like 3G modem, keyboard. The usb runtime suspend routine may be scheduled after the usb controller has been shut down, and the usb runtime suspend routine will try to suspend its roothub(controller), it will access register, then the system hang occurs as the controller is shutdown. Signed-off-by: Peter Chen Acked-by: Ming Lei Acked-by: Greg Kroah-Hartman Cc: stable@kernel.org Signed-off-by: Rafael J. Wysocki --- drivers/base/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 82c865452c70..d8b3d89db043 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -1742,6 +1743,8 @@ void device_shutdown(void) */ list_del_init(&dev->kobj.entry); spin_unlock(&devices_kset->list_lock); + /* Disable all device's runtime power management */ + pm_runtime_disable(dev); if (dev->bus && dev->bus->shutdown) { dev_dbg(dev, "shutdown\n"); -- 2.20.1