The FIXME is related to the wake-up workaround cancelation - do we
need the reschedule_work flag alongside the cancel_work_sync usage?
The teardown sequence is as described below:
Upon tty session termination:
ft260_uart_port_shutdown
ft260_uart_wakeup_workaraund_enable: deactivate wakeup workaround
t260_uart_cleanup
ft260_uart_port_put
On rmmod:
ft260_remove
cancel_work_sync
ft260_uart_port_remove
timer_delete_sync
ft260_uart_port_put
ft260_uart_port_destroy
The ft260_uart_start_wakeup timer_work can occur after the cancel_work_sync
returns, rescheduling the wakeup_work again. The reschedule_work flag set
earlier at the ft260_uart_port_shutdown time prevents it.
The alternative could be performing the timer_delete_sync first, preventing
the wakeup_timer and wakeup_work from rescheduling, and then canceling the
last wakeup_work by calling the cancel_work_sync. However, we still need the
reschedule_work flag to enable or bypass the power saving mode according to
the requested baud rate.
Signed-off-by: Michael Zaidman <michael.zaidman@xxxxxxxxx>
---
drivers/hid/hid-ft260.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 1c113f735524..52ccee83250e 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -1585,7 +1585,6 @@ static int ft260_uart_probe(struct hid_device *hdev, struct ft260_device *dev)
struct device *devt;
INIT_WORK(&dev->wakeup_work, ft260_uart_do_wakeup);
- // FIXME: Do I need that if I have cancel_work_sync?
// FIXME: are all kfifo access secured by lock? with irq or not?
ft260_uart_wakeup_workaraund_enable(dev, true);
/* Work not started at this point */
@@ -1721,7 +1720,6 @@ static void ft260_remove(struct hid_device *hdev)
return;
if (dev->iface_type == FT260_IFACE_UART) {
- // FIXME:
cancel_work_sync(&dev->wakeup_work);
tty_port_unregister_device(&dev->port, ft260_tty_driver,
dev->index);
--
2.40.1
