[PATCH] Driver Core: remove driver model detach_state

The driver model has a "detach_state" mechanism that:

 - Has never been used by any in-kernel drive;
 - Is superfluous, since driver remove() methods can do the same thing;
 - Became buggy when the suspend() parameter changed semantics and type;
 - Could self-deadlock when called from certain suspend contexts;
 - Is effectively wasted documentation, object code, and headspace.

This removes that "detach_state" mechanism; net code shrink, as well
as a per-device saving in the driver model and sysfs.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 0 insertions, 51 deletions

diff --git a/drivers/base/interface.c b/drivers/base/interface.c
deleted file mode 100644
index bd515843a0cb..000000000000
--- a/drivers/base/interface.c
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * drivers/base/interface.c - common driverfs interface that's exported to
- *      the world for all devices.
- *
- * Copyright (c) 2002-3 Patrick Mochel
- * Copyright (c) 2002-3 Open Source Development Labs
- *
- * This file is released under the GPLv2
- *
- */
-
-#include <linux/device.h>
-#include <linux/err.h>
-#include <linux/stat.h>
-#include <linux/string.h>
-
-/**
- *      detach_state - control the default power state for the device.
- *
- *      This is the state the device enters when it's driver module is
- *      unloaded. The value is an unsigned integer, in the range of 0-4.
- *      '0' indicates 'On', so no action will be taken when the driver is
- *      unloaded. This is the default behavior.
- *      '4' indicates 'Off', meaning the driver core will call the driver's
- *      shutdown method to quiesce the device.
- *      1-3 indicate a low-power state for the device to enter via the
- *      driver's suspend method.
- */
-
-static ssize_t detach_show(struct device * dev, char * buf)
-{
-        return sprintf(buf, "%u\n", dev->detach_state);
-}
-
-static ssize_t detach_store(struct device * dev, const char * buf, size_t n)
-{
-        u32 state;
-        state = simple_strtoul(buf, NULL, 10);
-        if (state > 4)
-                return -EINVAL;
-        dev->detach_state = state;
-        return n;
-}
-
-static DEVICE_ATTR(detach_state, 0644, detach_show, detach_store);
-
-
-struct attribute * dev_default_attrs[] = {
-        &dev_attr_detach_state.attr,
-        NULL,
-};