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linux/drivers/net/wireless/b43/rfkill.c
Michael Buesch 80fda03fc8 b43: Fix rfkill callback deadlock
wl->mutex might already be locked on initialization.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2007-11-10 04:25:12 -05:00

191 lines
4.8 KiB
C

/*
Broadcom B43 wireless driver
RFKILL support
Copyright (c) 2007 Michael Buesch <mb@bu3sch.de>
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, write to
the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "rfkill.h"
#include "b43.h"
/* Returns TRUE, if the radio is enabled in hardware. */
static bool b43_is_hw_radio_enabled(struct b43_wldev *dev)
{
if (dev->phy.rev >= 3) {
if (!(b43_read32(dev, B43_MMIO_RADIO_HWENABLED_HI)
& B43_MMIO_RADIO_HWENABLED_HI_MASK))
return 1;
} else {
if (b43_read16(dev, B43_MMIO_RADIO_HWENABLED_LO)
& B43_MMIO_RADIO_HWENABLED_LO_MASK)
return 1;
}
return 0;
}
/* The poll callback for the hardware button. */
static void b43_rfkill_poll(struct input_polled_dev *poll_dev)
{
struct b43_wldev *dev = poll_dev->private;
struct b43_wl *wl = dev->wl;
bool enabled;
mutex_lock(&wl->mutex);
B43_WARN_ON(b43_status(dev) < B43_STAT_INITIALIZED);
enabled = b43_is_hw_radio_enabled(dev);
if (unlikely(enabled != dev->radio_hw_enable)) {
dev->radio_hw_enable = enabled;
b43info(wl, "Radio hardware status changed to %s\n",
enabled ? "ENABLED" : "DISABLED");
mutex_unlock(&wl->mutex);
input_report_key(poll_dev->input, KEY_WLAN, enabled);
} else
mutex_unlock(&wl->mutex);
}
/* Called when the RFKILL toggled in software. */
static int b43_rfkill_soft_toggle(void *data, enum rfkill_state state)
{
struct b43_wldev *dev = data;
struct b43_wl *wl = dev->wl;
int err = 0;
/* When RFKILL is registered, it will call back into this callback.
* wl->mutex will already be locked when this happens.
* So first trylock. On contention check if we are in initialization.
* Silently return if that happens to avoid a deadlock. */
if (mutex_trylock(&wl->mutex) == 0) {
if (b43_status(dev) < B43_STAT_INITIALIZED)
return 0;
mutex_lock(&wl->mutex);
}
if (b43_status(dev) < B43_STAT_INITIALIZED)
goto out_unlock;
switch (state) {
case RFKILL_STATE_ON:
if (!dev->radio_hw_enable) {
/* No luck. We can't toggle the hardware RF-kill
* button from software. */
err = -EBUSY;
goto out_unlock;
}
if (!dev->phy.radio_on)
b43_radio_turn_on(dev);
break;
case RFKILL_STATE_OFF:
if (dev->phy.radio_on)
b43_radio_turn_off(dev, 0);
break;
}
out_unlock:
mutex_unlock(&wl->mutex);
return err;
}
char * b43_rfkill_led_name(struct b43_wldev *dev)
{
struct b43_wl *wl = dev->wl;
if (!wl->rfkill.rfkill)
return NULL;
return rfkill_get_led_name(wl->rfkill.rfkill);
}
void b43_rfkill_init(struct b43_wldev *dev)
{
struct b43_wl *wl = dev->wl;
struct b43_rfkill *rfk = &(wl->rfkill);
int err;
if (rfk->rfkill) {
err = rfkill_register(rfk->rfkill);
if (err) {
b43warn(wl, "Failed to register RF-kill button\n");
goto err_free_rfk;
}
}
if (rfk->poll_dev) {
err = input_register_polled_device(rfk->poll_dev);
if (err) {
b43warn(wl, "Failed to register RF-kill polldev\n");
goto err_free_polldev;
}
}
return;
err_free_rfk:
rfkill_free(rfk->rfkill);
rfk->rfkill = NULL;
err_free_polldev:
input_free_polled_device(rfk->poll_dev);
rfk->poll_dev = NULL;
}
void b43_rfkill_exit(struct b43_wldev *dev)
{
struct b43_rfkill *rfk = &(dev->wl->rfkill);
if (rfk->poll_dev)
input_unregister_polled_device(rfk->poll_dev);
if (rfk->rfkill)
rfkill_unregister(rfk->rfkill);
}
void b43_rfkill_alloc(struct b43_wldev *dev)
{
struct b43_wl *wl = dev->wl;
struct b43_rfkill *rfk = &(wl->rfkill);
snprintf(rfk->name, sizeof(rfk->name),
"b43-%s", wiphy_name(wl->hw->wiphy));
rfk->rfkill = rfkill_allocate(dev->dev->dev, RFKILL_TYPE_WLAN);
if (!rfk->rfkill) {
b43warn(wl, "Failed to allocate RF-kill button\n");
return;
}
rfk->rfkill->name = rfk->name;
rfk->rfkill->state = RFKILL_STATE_ON;
rfk->rfkill->data = dev;
rfk->rfkill->toggle_radio = b43_rfkill_soft_toggle;
rfk->rfkill->user_claim_unsupported = 1;
rfk->poll_dev = input_allocate_polled_device();
if (rfk->poll_dev) {
rfk->poll_dev->private = dev;
rfk->poll_dev->poll = b43_rfkill_poll;
rfk->poll_dev->poll_interval = 1000; /* msecs */
} else
b43warn(wl, "Failed to allocate RF-kill polldev\n");
}
void b43_rfkill_free(struct b43_wldev *dev)
{
struct b43_rfkill *rfk = &(dev->wl->rfkill);
input_free_polled_device(rfk->poll_dev);
rfk->poll_dev = NULL;
rfkill_free(rfk->rfkill);
rfk->rfkill = NULL;
}