linux/net/rfkill/input.c
Tejun Heo 41f63c5359 workqueue: use mod_delayed_work() instead of cancel + queue
Convert delayed_work users doing cancel_delayed_work() followed by
queue_delayed_work() to mod_delayed_work().

Most conversions are straight-forward.  Ones worth mentioning are,

* drivers/edac/edac_mc.c: edac_mc_workq_setup() converted to always
  use mod_delayed_work() and cancel loop in
  edac_mc_reset_delay_period() is dropped.

* drivers/platform/x86/thinkpad_acpi.c: No need to remember whether
  watchdog is active or not.  @fan_watchdog_active and related code
  dropped.

* drivers/power/charger-manager.c: Seemingly a lot of
  delayed_work_pending() abuse going on here.
  [delayed_]work_pending() are unsynchronized and racy when used like
  this.  I converted one instance in fullbatt_handler().  Please
  conver the rest so that it invokes workqueue APIs for the intended
  target state rather than trying to game work item pending state
  transitions.  e.g. if timer should be modified - call
  mod_delayed_work(), canceled - call cancel_delayed_work[_sync]().

* drivers/thermal/thermal_sys.c: thermal_zone_device_set_polling()
  simplified.  Note that round_jiffies() calls in this function are
  meaningless.  round_jiffies() work on absolute jiffies not delta
  delay used by delayed_work.

v2: Tomi pointed out that __cancel_delayed_work() users can't be
    safely converted to mod_delayed_work().  They could be calling it
    from irq context and if that happens while delayed_work_timer_fn()
    is running, it could deadlock.  __cancel_delayed_work() users are
    dropped.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Roland Dreier <roland@kernel.org>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
2012-08-13 16:27:37 -07:00

351 lines
8.8 KiB
C

/*
* Input layer to RF Kill interface connector
*
* Copyright (c) 2007 Dmitry Torokhov
* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* If you ever run into a situation in which you have a SW_ type rfkill
* input device, then you can revive code that was removed in the patch
* "rfkill-input: remove unused code".
*/
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/moduleparam.h>
#include <linux/workqueue.h>
#include <linux/init.h>
#include <linux/rfkill.h>
#include <linux/sched.h>
#include "rfkill.h"
enum rfkill_input_master_mode {
RFKILL_INPUT_MASTER_UNLOCK = 0,
RFKILL_INPUT_MASTER_RESTORE = 1,
RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
NUM_RFKILL_INPUT_MASTER_MODES
};
/* Delay (in ms) between consecutive switch ops */
#define RFKILL_OPS_DELAY 200
static enum rfkill_input_master_mode rfkill_master_switch_mode =
RFKILL_INPUT_MASTER_UNBLOCKALL;
module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
MODULE_PARM_DESC(master_switch_mode,
"SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
static spinlock_t rfkill_op_lock;
static bool rfkill_op_pending;
static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
enum rfkill_sched_op {
RFKILL_GLOBAL_OP_EPO = 0,
RFKILL_GLOBAL_OP_RESTORE,
RFKILL_GLOBAL_OP_UNLOCK,
RFKILL_GLOBAL_OP_UNBLOCK,
};
static enum rfkill_sched_op rfkill_master_switch_op;
static enum rfkill_sched_op rfkill_op;
static void __rfkill_handle_global_op(enum rfkill_sched_op op)
{
unsigned int i;
switch (op) {
case RFKILL_GLOBAL_OP_EPO:
rfkill_epo();
break;
case RFKILL_GLOBAL_OP_RESTORE:
rfkill_restore_states();
break;
case RFKILL_GLOBAL_OP_UNLOCK:
rfkill_remove_epo_lock();
break;
case RFKILL_GLOBAL_OP_UNBLOCK:
rfkill_remove_epo_lock();
for (i = 0; i < NUM_RFKILL_TYPES; i++)
rfkill_switch_all(i, false);
break;
default:
/* memory corruption or bug, fail safely */
rfkill_epo();
WARN(1, "Unknown requested operation %d! "
"rfkill Emergency Power Off activated\n",
op);
}
}
static void __rfkill_handle_normal_op(const enum rfkill_type type,
const bool complement)
{
bool blocked;
blocked = rfkill_get_global_sw_state(type);
if (complement)
blocked = !blocked;
rfkill_switch_all(type, blocked);
}
static void rfkill_op_handler(struct work_struct *work)
{
unsigned int i;
bool c;
spin_lock_irq(&rfkill_op_lock);
do {
if (rfkill_op_pending) {
enum rfkill_sched_op op = rfkill_op;
rfkill_op_pending = false;
memset(rfkill_sw_pending, 0,
sizeof(rfkill_sw_pending));
spin_unlock_irq(&rfkill_op_lock);
__rfkill_handle_global_op(op);
spin_lock_irq(&rfkill_op_lock);
/*
* handle global ops first -- during unlocked period
* we might have gotten a new global op.
*/
if (rfkill_op_pending)
continue;
}
if (rfkill_is_epo_lock_active())
continue;
for (i = 0; i < NUM_RFKILL_TYPES; i++) {
if (__test_and_clear_bit(i, rfkill_sw_pending)) {
c = __test_and_clear_bit(i, rfkill_sw_state);
spin_unlock_irq(&rfkill_op_lock);
__rfkill_handle_normal_op(i, c);
spin_lock_irq(&rfkill_op_lock);
}
}
} while (rfkill_op_pending);
spin_unlock_irq(&rfkill_op_lock);
}
static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
static unsigned long rfkill_last_scheduled;
static unsigned long rfkill_ratelimit(const unsigned long last)
{
const unsigned long delay = msecs_to_jiffies(RFKILL_OPS_DELAY);
return time_after(jiffies, last + delay) ? 0 : delay;
}
static void rfkill_schedule_ratelimited(void)
{
if (delayed_work_pending(&rfkill_op_work))
return;
schedule_delayed_work(&rfkill_op_work,
rfkill_ratelimit(rfkill_last_scheduled));
rfkill_last_scheduled = jiffies;
}
static void rfkill_schedule_global_op(enum rfkill_sched_op op)
{
unsigned long flags;
spin_lock_irqsave(&rfkill_op_lock, flags);
rfkill_op = op;
rfkill_op_pending = true;
if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
/* bypass the limiter for EPO */
mod_delayed_work(system_wq, &rfkill_op_work, 0);
rfkill_last_scheduled = jiffies;
} else
rfkill_schedule_ratelimited();
spin_unlock_irqrestore(&rfkill_op_lock, flags);
}
static void rfkill_schedule_toggle(enum rfkill_type type)
{
unsigned long flags;
if (rfkill_is_epo_lock_active())
return;
spin_lock_irqsave(&rfkill_op_lock, flags);
if (!rfkill_op_pending) {
__set_bit(type, rfkill_sw_pending);
__change_bit(type, rfkill_sw_state);
rfkill_schedule_ratelimited();
}
spin_unlock_irqrestore(&rfkill_op_lock, flags);
}
static void rfkill_schedule_evsw_rfkillall(int state)
{
if (state)
rfkill_schedule_global_op(rfkill_master_switch_op);
else
rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
}
static void rfkill_event(struct input_handle *handle, unsigned int type,
unsigned int code, int data)
{
if (type == EV_KEY && data == 1) {
switch (code) {
case KEY_WLAN:
rfkill_schedule_toggle(RFKILL_TYPE_WLAN);
break;
case KEY_BLUETOOTH:
rfkill_schedule_toggle(RFKILL_TYPE_BLUETOOTH);
break;
case KEY_UWB:
rfkill_schedule_toggle(RFKILL_TYPE_UWB);
break;
case KEY_WIMAX:
rfkill_schedule_toggle(RFKILL_TYPE_WIMAX);
break;
case KEY_RFKILL:
rfkill_schedule_toggle(RFKILL_TYPE_ALL);
break;
}
} else if (type == EV_SW && code == SW_RFKILL_ALL)
rfkill_schedule_evsw_rfkillall(data);
}
static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
const struct input_device_id *id)
{
struct input_handle *handle;
int error;
handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
if (!handle)
return -ENOMEM;
handle->dev = dev;
handle->handler = handler;
handle->name = "rfkill";
/* causes rfkill_start() to be called */
error = input_register_handle(handle);
if (error)
goto err_free_handle;
error = input_open_device(handle);
if (error)
goto err_unregister_handle;
return 0;
err_unregister_handle:
input_unregister_handle(handle);
err_free_handle:
kfree(handle);
return error;
}
static void rfkill_start(struct input_handle *handle)
{
/*
* Take event_lock to guard against configuration changes, we
* should be able to deal with concurrency with rfkill_event()
* just fine (which event_lock will also avoid).
*/
spin_lock_irq(&handle->dev->event_lock);
if (test_bit(EV_SW, handle->dev->evbit) &&
test_bit(SW_RFKILL_ALL, handle->dev->swbit))
rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
handle->dev->sw));
spin_unlock_irq(&handle->dev->event_lock);
}
static void rfkill_disconnect(struct input_handle *handle)
{
input_close_device(handle);
input_unregister_handle(handle);
kfree(handle);
}
static const struct input_device_id rfkill_ids[] = {
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
.evbit = { BIT_MASK(EV_KEY) },
.keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
},
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
.evbit = { BIT_MASK(EV_KEY) },
.keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
},
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
.evbit = { BIT_MASK(EV_KEY) },
.keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
},
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
.evbit = { BIT_MASK(EV_KEY) },
.keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
},
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
.evbit = { BIT_MASK(EV_KEY) },
.keybit = { [BIT_WORD(KEY_RFKILL)] = BIT_MASK(KEY_RFKILL) },
},
{
.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
.evbit = { BIT(EV_SW) },
.swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
},
{ }
};
static struct input_handler rfkill_handler = {
.name = "rfkill",
.event = rfkill_event,
.connect = rfkill_connect,
.start = rfkill_start,
.disconnect = rfkill_disconnect,
.id_table = rfkill_ids,
};
int __init rfkill_handler_init(void)
{
switch (rfkill_master_switch_mode) {
case RFKILL_INPUT_MASTER_UNBLOCKALL:
rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNBLOCK;
break;
case RFKILL_INPUT_MASTER_RESTORE:
rfkill_master_switch_op = RFKILL_GLOBAL_OP_RESTORE;
break;
case RFKILL_INPUT_MASTER_UNLOCK:
rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNLOCK;
break;
default:
return -EINVAL;
}
spin_lock_init(&rfkill_op_lock);
/* Avoid delay at first schedule */
rfkill_last_scheduled =
jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
return input_register_handler(&rfkill_handler);
}
void __exit rfkill_handler_exit(void)
{
input_unregister_handler(&rfkill_handler);
cancel_delayed_work_sync(&rfkill_op_work);
}