[PATCH] input-polldev: Poll interval setting can cause polling with zero interval
From: Samu Onkalo <hidden>
Date: 2009-11-23 11:22:06
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
If the poll interval is set to 0 via new sysfs entry and device is opened after that, polling is started with interval 0. This causes huge CPU load. Same happens if the rate was 0 when the device was closed and then reopened. Applies to input-tree next branch Signed-off-by: Samu Onkalo <redacted> --- drivers/input/input-polldev.c | 17 ++++++++--------- 1 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/input/input-polldev.c b/drivers/input/input-polldev.c
index 3187427..2d2c626 100644
--- a/drivers/input/input-polldev.c
+++ b/drivers/input/input-polldev.c@@ -59,12 +59,13 @@ static void input_polldev_stop_workqueue(void) static void input_polldev_queue_work(struct input_polled_dev *dev) { unsigned long delay; + if (dev->poll_interval > 0) { + delay = msecs_to_jiffies(dev->poll_interval); + if (delay >= HZ) + delay = round_jiffies_relative(delay); - delay = msecs_to_jiffies(dev->poll_interval); - if (delay >= HZ) - delay = round_jiffies_relative(delay); - - queue_delayed_work(polldev_wq, &dev->work, delay); + queue_delayed_work(polldev_wq, &dev->work, delay); + } } static void input_polled_device_work(struct work_struct *work)
@@ -88,8 +89,7 @@ static int input_open_polled_device(struct input_dev *input) if (dev->open) dev->open(dev); - queue_delayed_work(polldev_wq, &dev->work, - msecs_to_jiffies(dev->poll_interval)); + input_polldev_queue_work(dev); return 0; }
@@ -138,8 +138,7 @@ static ssize_t input_polldev_set_poll(struct device *dev, if (input->users) { cancel_delayed_work_sync(&polldev->work); - if (polldev->poll_interval > 0) - input_polldev_queue_work(polldev); + input_polldev_queue_work(polldev); } mutex_unlock(&input->mutex);
--
1.6.0.4