kernel-ark/drivers/net/wireless/ath/ar9170/led.c
Christian Lamparter 6d7db193f2 ar9170: cancel led worker properly on exit
"[PATCH 3/4 v2] ar9170: fix LED power state handling" revealed
a bug which can cause a ugly crash.

The delayed worker is canceled before the LED class functions are
unregistered... So, if something manages to update the LEDs
while unregister routine is running the timer could fire _after_ the
module has been unloaded.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-06-03 14:05:15 -04:00

179 lines
4.7 KiB
C

/*
* Atheros AR9170 driver
*
* LED handling
*
* Copyright 2008, 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 as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, see
* http://www.gnu.org/licenses/.
*
* This file incorporates work covered by the following copyright and
* permission notice:
* Copyright (c) 2007-2008 Atheros Communications, Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "ar9170.h"
#include "cmd.h"
int ar9170_set_leds_state(struct ar9170 *ar, u32 led_state)
{
return ar9170_write_reg(ar, AR9170_GPIO_REG_DATA, led_state);
}
int ar9170_init_leds(struct ar9170 *ar)
{
int err;
/* disable LEDs */
/* GPIO [0/1 mode: output, 2/3: input] */
err = ar9170_write_reg(ar, AR9170_GPIO_REG_PORT_TYPE, 3);
if (err)
goto out;
/* GPIO 0/1 value: off */
err = ar9170_set_leds_state(ar, 0);
out:
return err;
}
#ifdef CONFIG_AR9170_LEDS
static void ar9170_update_leds(struct work_struct *work)
{
struct ar9170 *ar = container_of(work, struct ar9170, led_work.work);
int i, tmp, blink_delay = 1000;
u32 led_val = 0;
bool rerun = false;
if (unlikely(!IS_ACCEPTING_CMD(ar)))
return ;
mutex_lock(&ar->mutex);
for (i = 0; i < AR9170_NUM_LEDS; i++)
if (ar->leds[i].registered && ar->leds[i].toggled) {
led_val |= 1 << i;
tmp = 70 + 200 / (ar->leds[i].toggled);
if (tmp < blink_delay)
blink_delay = tmp;
if (ar->leds[i].toggled > 1)
ar->leds[i].toggled = 0;
rerun = true;
}
ar9170_set_leds_state(ar, led_val);
mutex_unlock(&ar->mutex);
if (rerun)
queue_delayed_work(ar->hw->workqueue, &ar->led_work,
msecs_to_jiffies(blink_delay));
}
static void ar9170_led_brightness_set(struct led_classdev *led,
enum led_brightness brightness)
{
struct ar9170_led *arl = container_of(led, struct ar9170_led, l);
struct ar9170 *ar = arl->ar;
if (unlikely(!arl->registered))
return ;
if (arl->last_state != !!brightness) {
arl->toggled++;
arl->last_state = !!brightness;
}
if (likely(IS_ACCEPTING_CMD(ar) && arl->toggled))
queue_delayed_work(ar->hw->workqueue, &ar->led_work, HZ/10);
}
static int ar9170_register_led(struct ar9170 *ar, int i, char *name,
char *trigger)
{
int err;
snprintf(ar->leds[i].name, sizeof(ar->leds[i].name),
"ar9170-%s::%s", wiphy_name(ar->hw->wiphy), name);
ar->leds[i].ar = ar;
ar->leds[i].l.name = ar->leds[i].name;
ar->leds[i].l.brightness_set = ar9170_led_brightness_set;
ar->leds[i].l.brightness = 0;
ar->leds[i].l.default_trigger = trigger;
err = led_classdev_register(wiphy_dev(ar->hw->wiphy),
&ar->leds[i].l);
if (err)
printk(KERN_ERR "%s: failed to register %s LED (%d).\n",
wiphy_name(ar->hw->wiphy), ar->leds[i].name, err);
else
ar->leds[i].registered = true;
return err;
}
void ar9170_unregister_leds(struct ar9170 *ar)
{
int i;
for (i = 0; i < AR9170_NUM_LEDS; i++)
if (ar->leds[i].registered) {
led_classdev_unregister(&ar->leds[i].l);
ar->leds[i].registered = false;
ar->leds[i].toggled = 0;
}
cancel_delayed_work_sync(&ar->led_work);
}
int ar9170_register_leds(struct ar9170 *ar)
{
int err;
INIT_DELAYED_WORK(&ar->led_work, ar9170_update_leds);
err = ar9170_register_led(ar, 0, "tx",
ieee80211_get_tx_led_name(ar->hw));
if (err)
goto fail;
err = ar9170_register_led(ar, 1, "assoc",
ieee80211_get_assoc_led_name(ar->hw));
if (err)
goto fail;
return 0;
fail:
ar9170_unregister_leds(ar);
return err;
}
#endif /* CONFIG_AR9170_LEDS */