android_kernel_xiaomi_sm8350/drivers/base/power/shutdown.c
Michael Richardson 9c08a938ce [PATCH] device_shutdown can loop if the driver frees itself
This patch changes device_shutdown() to use the newly introduced safe
reverse list traversal.  We experienced loops on system reboot if we had
removed and re-inserted our device from the device list.

We noticed this problem on PPC405. Our PCI IDE device comes and goes a lot.

Our hypothesis was that there was a loop caused by the driver->shutdown
freeing memory.  It is possible that we do something wrong as well, but
being unable to reboot is kind of nasty.

Signed-off-by: Michael Richardson <mcr@marajade.sandelman.ca>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13 11:26:12 -08:00

56 lines
1.3 KiB
C

/*
* shutdown.c - power management functions for the device tree.
*
* Copyright (c) 2002-3 Patrick Mochel
* 2002-3 Open Source Development Lab
*
* This file is released under the GPLv2
*
*/
#include <linux/config.h>
#include <linux/device.h>
#include <asm/semaphore.h>
#include "power.h"
#define to_dev(node) container_of(node, struct device, kobj.entry)
extern struct subsystem devices_subsys;
/**
* We handle system devices differently - we suspend and shut them
* down last and resume them first. That way, we don't do anything stupid like
* shutting down the interrupt controller before any devices..
*
* Note that there are not different stages for power management calls -
* they only get one called once when interrupts are disabled.
*/
extern int sysdev_shutdown(void);
/**
* device_shutdown - call ->shutdown() on each device to shutdown.
*/
void device_shutdown(void)
{
struct device * dev, *devn;
down_write(&devices_subsys.rwsem);
list_for_each_entry_safe_reverse(dev, devn, &devices_subsys.kset.list,
kobj.entry) {
if (dev->bus && dev->bus->shutdown) {
dev_dbg(dev, "shutdown\n");
dev->bus->shutdown(dev);
} else if (dev->driver && dev->driver->shutdown) {
dev_dbg(dev, "shutdown\n");
dev->driver->shutdown(dev);
}
}
up_write(&devices_subsys.rwsem);
sysdev_shutdown();
}