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thinkpad-acpi: hotkey poll fixes
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Fix some locking, avoid exiting the kthread before kthread_stop() is
called on it, and clean up the hotkey poll routines a little bit.

Also, restore bits in the firmware mask after hotkey_source_mask is
changed.  Without this, we leave events disabled...

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
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Henrique de Moraes Holschuh authored and Len Brown committed Sep 19, 2009
1 parent e675aba commit db25f16
Showing 1 changed file with 73 additions and 35 deletions.
108 changes: 73 additions & 35 deletions drivers/platform/x86/thinkpad_acpi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1922,16 +1922,42 @@ struct tp_nvram_state {
u8 volume_level;
};

/* kthread for the hotkey poller */
static struct task_struct *tpacpi_hotkey_task;
static u32 hotkey_source_mask; /* bit mask 0=ACPI,1=NVRAM */
static int hotkey_poll_freq = 10; /* Hz */

/* Acquired while the poller kthread is running, use to sync start/stop */
static struct mutex hotkey_thread_mutex;

/*
* Acquire mutex to write poller control variables.
* Increment hotkey_config_change when changing them.
*
* See HOTKEY_CONFIG_CRITICAL_START/HOTKEY_CONFIG_CRITICAL_END
*/
static struct mutex hotkey_thread_data_mutex;
static unsigned int hotkey_config_change;

/*
* hotkey poller control variables
*
* Must be atomic or readers will also need to acquire mutex
*/
static u32 hotkey_source_mask; /* bit mask 0=ACPI,1=NVRAM */
static unsigned int hotkey_poll_freq = 10; /* Hz */

#define HOTKEY_CONFIG_CRITICAL_START \
do { \
mutex_lock(&hotkey_thread_data_mutex); \
hotkey_config_change++; \
} while (0);
#define HOTKEY_CONFIG_CRITICAL_END \
mutex_unlock(&hotkey_thread_data_mutex);

#else /* CONFIG_THINKPAD_ACPI_HOTKEY_POLL */

#define hotkey_source_mask 0U
#define HOTKEY_CONFIG_CRITICAL_START
#define HOTKEY_CONFIG_CRITICAL_END

#endif /* CONFIG_THINKPAD_ACPI_HOTKEY_POLL */

Expand All @@ -1956,19 +1982,6 @@ static u16 *hotkey_keycode_map;

static struct attribute_set *hotkey_dev_attributes;

#ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL
#define HOTKEY_CONFIG_CRITICAL_START \
do { \
mutex_lock(&hotkey_thread_data_mutex); \
hotkey_config_change++; \
} while (0);
#define HOTKEY_CONFIG_CRITICAL_END \
mutex_unlock(&hotkey_thread_data_mutex);
#else
#define HOTKEY_CONFIG_CRITICAL_START
#define HOTKEY_CONFIG_CRITICAL_END
#endif /* CONFIG_THINKPAD_ACPI_HOTKEY_POLL */

/* HKEY.MHKG() return bits */
#define TP_HOTKEY_TABLET_MASK (1 << 3)

Expand Down Expand Up @@ -2013,7 +2026,9 @@ static int hotkey_mask_get(void)
if (!acpi_evalf(hkey_handle, &m, "DHKN", "d"))
return -EIO;
}
HOTKEY_CONFIG_CRITICAL_START
hotkey_mask = m | (hotkey_source_mask & hotkey_mask);
HOTKEY_CONFIG_CRITICAL_END

return 0;
}
Expand Down Expand Up @@ -2266,6 +2281,7 @@ static int hotkey_kthread(void *data)
unsigned int si, so;
unsigned long t;
unsigned int change_detector, must_reset;
unsigned int poll_freq;

mutex_lock(&hotkey_thread_mutex);

Expand All @@ -2282,12 +2298,17 @@ static int hotkey_kthread(void *data)
mutex_lock(&hotkey_thread_data_mutex);
change_detector = hotkey_config_change;
mask = hotkey_source_mask & hotkey_mask;
poll_freq = hotkey_poll_freq;
mutex_unlock(&hotkey_thread_data_mutex);
hotkey_read_nvram(&s[so], mask);

while (!kthread_should_stop() && hotkey_poll_freq) {
if (t == 0)
t = 1000/hotkey_poll_freq;
while (!kthread_should_stop()) {
if (t == 0) {
if (likely(poll_freq))
t = 1000/poll_freq;
else
t = 100; /* should never happen... */
}
t = msleep_interruptible(t);
if (unlikely(kthread_should_stop()))
break;
Expand All @@ -2303,6 +2324,7 @@ static int hotkey_kthread(void *data)
change_detector = hotkey_config_change;
}
mask = hotkey_source_mask & hotkey_mask;
poll_freq = hotkey_poll_freq;
mutex_unlock(&hotkey_thread_data_mutex);

if (likely(mask)) {
Expand All @@ -2322,6 +2344,7 @@ static int hotkey_kthread(void *data)
return 0;
}

/* call with hotkey_mutex held */
static void hotkey_poll_stop_sync(void)
{
if (tpacpi_hotkey_task) {
Expand All @@ -2338,10 +2361,11 @@ static void hotkey_poll_stop_sync(void)
}

/* call with hotkey_mutex held */
static void hotkey_poll_setup(int may_warn)
static void hotkey_poll_setup(bool may_warn)
{
if ((hotkey_source_mask & hotkey_mask) != 0 &&
hotkey_poll_freq > 0 &&
u32 hotkeys_to_poll = hotkey_source_mask & hotkey_mask;

if (hotkeys_to_poll != 0 && hotkey_poll_freq > 0 &&
(tpacpi_inputdev->users > 0 || hotkey_report_mode < 2)) {
if (!tpacpi_hotkey_task) {
tpacpi_hotkey_task = kthread_run(hotkey_kthread,
Expand All @@ -2355,26 +2379,37 @@ static void hotkey_poll_setup(int may_warn)
}
} else {
hotkey_poll_stop_sync();
if (may_warn &&
hotkey_source_mask != 0 && hotkey_poll_freq == 0) {
if (may_warn && hotkeys_to_poll != 0 &&
hotkey_poll_freq == 0) {
printk(TPACPI_NOTICE
"hot keys 0x%08x require polling, "
"which is currently disabled\n",
hotkey_source_mask);
hotkeys_to_poll);
}
}
}

static void hotkey_poll_setup_safe(int may_warn)
static void hotkey_poll_setup_safe(bool may_warn)
{
mutex_lock(&hotkey_mutex);
hotkey_poll_setup(may_warn);
mutex_unlock(&hotkey_mutex);
}

/* call with hotkey_mutex held */
static void hotkey_poll_set_freq(unsigned int freq)
{
if (!freq)
hotkey_poll_stop_sync();

HOTKEY_CONFIG_CRITICAL_START
hotkey_poll_freq = freq;
HOTKEY_CONFIG_CRITICAL_END
}

#else /* CONFIG_THINKPAD_ACPI_HOTKEY_POLL */

static void hotkey_poll_setup_safe(int __unused)
static void hotkey_poll_setup_safe(bool __unused)
{
}

Expand All @@ -2392,7 +2427,7 @@ static int hotkey_inputdev_open(struct input_dev *dev)
case TPACPI_LIFE_EXITING:
return -EBUSY;
case TPACPI_LIFE_RUNNING:
hotkey_poll_setup_safe(0);
hotkey_poll_setup_safe(false);
return 0;
}

Expand All @@ -2405,7 +2440,7 @@ static void hotkey_inputdev_close(struct input_dev *dev)
{
/* disable hotkey polling when possible */
if (tpacpi_lifecycle == TPACPI_LIFE_RUNNING)
hotkey_poll_setup_safe(0);
hotkey_poll_setup_safe(false);
}

/* sysfs hotkey enable ------------------------------------------------- */
Expand Down Expand Up @@ -2479,7 +2514,7 @@ static ssize_t hotkey_mask_store(struct device *dev,
res = hotkey_mask_set(t);

#ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL
hotkey_poll_setup(1);
hotkey_poll_setup(true);
#endif

mutex_unlock(&hotkey_mutex);
Expand Down Expand Up @@ -2568,7 +2603,8 @@ static ssize_t hotkey_source_mask_store(struct device *dev,
hotkey_source_mask = t;
HOTKEY_CONFIG_CRITICAL_END

hotkey_poll_setup(1);
hotkey_poll_setup(true);
hotkey_mask_set(hotkey_mask);

mutex_unlock(&hotkey_mutex);

Expand Down Expand Up @@ -2601,9 +2637,9 @@ static ssize_t hotkey_poll_freq_store(struct device *dev,
if (mutex_lock_killable(&hotkey_mutex))
return -ERESTARTSYS;

hotkey_poll_freq = t;
hotkey_poll_set_freq(t);
hotkey_poll_setup(true);

hotkey_poll_setup(1);
mutex_unlock(&hotkey_mutex);

tpacpi_disclose_usertask("hotkey_poll_freq", "set to %lu\n", t);
Expand Down Expand Up @@ -2794,7 +2830,9 @@ static void tpacpi_send_radiosw_update(void)
static void hotkey_exit(void)
{
#ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL
mutex_lock(&hotkey_mutex);
hotkey_poll_stop_sync();
mutex_unlock(&hotkey_mutex);
#endif

if (hotkey_dev_attributes)
Expand Down Expand Up @@ -3031,7 +3069,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
}

vdbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_HKEY,
"hotkey source mask 0x%08x, polling freq %d\n",
"hotkey source mask 0x%08x, polling freq %u\n",
hotkey_source_mask, hotkey_poll_freq);
#endif

Expand Down Expand Up @@ -3169,7 +3207,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
tpacpi_inputdev->open = &hotkey_inputdev_open;
tpacpi_inputdev->close = &hotkey_inputdev_close;

hotkey_poll_setup_safe(1);
hotkey_poll_setup_safe(true);
tpacpi_send_radiosw_update();
tpacpi_input_send_tabletsw();

Expand Down Expand Up @@ -3457,7 +3495,7 @@ static void hotkey_resume(void)
hotkey_tablet_mode_notify_change();
hotkey_wakeup_reason_notify_change();
hotkey_wakeup_hotunplug_complete_notify_change();
hotkey_poll_setup_safe(0);
hotkey_poll_setup_safe(false);
}

/* procfs -------------------------------------------------------------- */
Expand Down

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