On 2020-05-08 16:37, Daniel Mack wrote:
Use a threaded IRQ handler to get rid of the irq_work kthread.
This also allows for the driver to use interrupts generated by
a threaded controller.
Signed-off-by: Daniel Mack <daniel@xxxxxxxxxx>
---
drivers/tty/serial/sc16is7xx.c | 18 +++++-------------
1 file changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c
b/drivers/tty/serial/sc16is7xx.c
index 0997a5cac02a..e3c5b9501764 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -328,7 +328,6 @@ struct sc16is7xx_port {
unsigned char buf[SC16IS7XX_FIFO_SIZE];
struct kthread_worker kworker;
struct task_struct *kworker_task;
- struct kthread_work irq_work;
struct mutex efr_lock;
struct sc16is7xx_one p[0];
};
@@ -711,9 +710,9 @@ static bool sc16is7xx_port_irq(struct
sc16is7xx_port *s, int portno)
return true;
}
-static void sc16is7xx_ist(struct kthread_work *ws)
+static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
{
- struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work);
+ struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
mutex_lock(&s->efr_lock);
@@ -728,13 +727,6 @@ static void sc16is7xx_ist(struct kthread_work *ws)
}
mutex_unlock(&s->efr_lock);
-}
-
-static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
-{
- struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
-
- kthread_queue_work(&s->kworker, &s->irq_work);
return IRQ_HANDLED;
}
@@ -1230,7 +1222,6 @@ static int sc16is7xx_probe(struct device *dev,
mutex_init(&s->efr_lock);
kthread_init_worker(&s->kworker);
- kthread_init_work(&s->irq_work, sc16is7xx_ist);
s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
"sc16is7xx");
if (IS_ERR(s->kworker_task)) {
@@ -1317,8 +1308,9 @@ static int sc16is7xx_probe(struct device *dev,
}
/* Setup interrupt */
- ret = devm_request_irq(dev, irq, sc16is7xx_irq,
- IRQF_TRIGGER_FALLING, dev_name(dev), s);
+ ret = devm_request_threaded_irq(dev, irq, NULL, sc16is7xx_irq,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ dev_name(dev), s);
if (!ret)
return 0;
Since UART0 is first handled completely in the for loop before UART1 is
handled, a new interrupt may arise on UART0 while UART1 is being
handled.
The result is a missed interrupt since the IRQ line might not *FALL*
again.
Therefor I suggest to change IRQF_TRIGGER_FALLING to IRQF_TRIGGER_LOW.
This
way the thread will be retriggered after IRQ_HANDLED is returned.
Maarten
