media: cec-pin: fix irq handling
The free_irq() function could be called from interrupt context,
which is invalid. Move this to the thread.
In the interrupt handler we just request that the thread disables
the irq. This is done through an atomic so we don't need to add
any spinlocks.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/media/cec/cec-pin.c b/drivers/media/cec/cec-pin.c
index 31a26d3..970774d 100644
--- a/drivers/media/cec/cec-pin.c
+++ b/drivers/media/cec/cec-pin.c
@@ -557,7 +557,7 @@
adap->is_configured || adap->monitor_all_cnt)
break;
/* Switch to interrupt mode */
- pin->work_enable_irq = true;
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_ENABLE);
pin->state = CEC_ST_RX_IRQ;
wake_up_interruptible(&pin->kthread_waitq);
return HRTIMER_NORESTART;
@@ -591,7 +591,7 @@
kthread_should_stop() ||
pin->work_rx_msg.len ||
pin->work_tx_status ||
- pin->work_enable_irq ||
+ atomic_read(&pin->work_irq_change) ||
atomic_read(&pin->work_pin_events));
if (pin->work_rx_msg.len) {
@@ -606,6 +606,7 @@
cec_transmit_attempt_done_ts(adap, tx_status,
pin->work_tx_ts);
}
+
while (atomic_read(&pin->work_pin_events)) {
unsigned int idx = pin->work_pin_events_rd;
@@ -615,14 +616,26 @@
pin->work_pin_events_rd = (idx + 1) % CEC_NUM_PIN_EVENTS;
atomic_dec(&pin->work_pin_events);
}
- if (pin->work_enable_irq) {
- pin->work_enable_irq = false;
+
+ switch (atomic_xchg(&pin->work_irq_change,
+ CEC_PIN_IRQ_UNCHANGED)) {
+ case CEC_PIN_IRQ_DISABLE:
+ pin->ops->disable_irq(adap);
+ cec_pin_high(pin);
+ cec_pin_to_idle(pin);
+ hrtimer_start(&pin->timer, 0, HRTIMER_MODE_REL);
+ break;
+ case CEC_PIN_IRQ_ENABLE:
pin->enable_irq_failed = !pin->ops->enable_irq(adap);
if (pin->enable_irq_failed) {
cec_pin_to_idle(pin);
hrtimer_start(&pin->timer, 0, HRTIMER_MODE_REL);
}
+ break;
+ default:
+ break;
}
+
if (kthread_should_stop())
break;
}
@@ -641,7 +654,7 @@
cec_pin_to_idle(pin);
pin->tx_msg.len = 0;
pin->timer_ts = 0;
- pin->work_enable_irq = false;
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED);
pin->kthread = kthread_run(cec_pin_thread_func, adap,
"cec-pin");
if (IS_ERR(pin->kthread)) {
@@ -682,7 +695,7 @@
pin->work_tx_status = 0;
pin->tx_bit = 0;
if (pin->state == CEC_ST_RX_IRQ) {
- pin->work_enable_irq = false;
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED);
pin->ops->disable_irq(adap);
cec_pin_high(pin);
cec_pin_to_idle(pin);
@@ -745,13 +758,8 @@
cec_pin_update(pin, value, false);
if (!value && (adap->is_configuring || adap->is_configured ||
- adap->monitor_all_cnt)) {
- pin->work_enable_irq = false;
- pin->ops->disable_irq(adap);
- cec_pin_high(pin);
- cec_pin_to_idle(pin);
- hrtimer_start(&pin->timer, 0, HRTIMER_MODE_REL);
- }
+ adap->monitor_all_cnt))
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_DISABLE);
}
EXPORT_SYMBOL_GPL(cec_pin_changed);