From d2f0a48f36aea38e0a5c4b439d5d9c96aecabad9 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Fri, 4 Oct 2013 12:07:00 +0100 Subject: [PATCH] iio: Wakeup poll and blocking reads when the device is unregistered Once the device has been unregistered there won't be any new data no matter how long a userspace application waits, so we might as well wake them up and let them know. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/iio/iio_core.h | 3 +++ drivers/iio/industrialio-buffer.c | 16 ++++++++++++++++ drivers/iio/industrialio-core.c | 4 ++++ drivers/iio/industrialio-event.c | 21 ++++++++++++++++++++- 4 files changed, 43 insertions(+), 1 deletion(-) diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h index 9209f47..7512cf7 100644 --- a/drivers/iio/iio_core.h +++ b/drivers/iio/iio_core.h @@ -50,6 +50,7 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, #define iio_buffer_read_first_n_outer_addr (&iio_buffer_read_first_n_outer) void iio_disable_all_buffers(struct iio_dev *indio_dev); +void iio_buffer_wakeup_poll(struct iio_dev *indio_dev); #else @@ -57,11 +58,13 @@ void iio_disable_all_buffers(struct iio_dev *indio_dev); #define iio_buffer_read_first_n_outer_addr NULL static inline void iio_disable_all_buffers(struct iio_dev *indio_dev) {} +static inline void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) {} #endif int iio_device_register_eventset(struct iio_dev *indio_dev); void iio_device_unregister_eventset(struct iio_dev *indio_dev); +void iio_device_wakeup_eventset(struct iio_dev *indio_dev); int iio_event_getfd(struct iio_dev *indio_dev); #endif diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 6c7a9c5..5a46c57 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include "iio_core.h" @@ -75,6 +76,21 @@ unsigned int iio_buffer_poll(struct file *filp, return 0; } +/** + * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue + * @indio_dev: The IIO device + * + * Wakes up the event waitqueue used for poll(). Should usually + * be called when the device is unregistered. + */ +void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) +{ + if (!indio_dev->buffer) + return; + + wake_up(&indio_dev->buffer->pollq); +} + void iio_buffer_init(struct iio_buffer *buffer) { INIT_LIST_HEAD(&buffer->demux_list); diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index a019a7b..dc24a9b 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -1139,6 +1139,10 @@ void iio_device_unregister(struct iio_dev *indio_dev) iio_disable_all_buffers(indio_dev); indio_dev->info = NULL; + + iio_device_wakeup_eventset(indio_dev); + iio_buffer_wakeup_poll(indio_dev); + mutex_unlock(&indio_dev->info_exist_lock); } EXPORT_SYMBOL(iio_device_unregister); diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c index 837d450..d251f30 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -113,9 +113,14 @@ static ssize_t iio_event_chrdev_read(struct file *filep, } /* Blocking on device; waiting for something to be there */ ret = wait_event_interruptible_locked_irq(ev_int->wait, - !kfifo_is_empty(&ev_int->det_events)); + !kfifo_is_empty(&ev_int->det_events) || + indio_dev->info == NULL); if (ret) goto error_unlock; + if (indio_dev->info == NULL) { + ret = -ENODEV; + goto error_unlock; + } /* Single access device so no one else can get the data */ } @@ -454,6 +459,20 @@ error_ret: return ret; } +/** + * iio_device_wakeup_eventset - Wakes up the event waitqueue + * @indio_dev: The IIO device + * + * Wakes up the event waitqueue used for poll() and blocking read(). + * Should usually be called when the device is unregistered. + */ +void iio_device_wakeup_eventset(struct iio_dev *indio_dev) +{ + if (indio_dev->event_interface == NULL) + return; + wake_up(&indio_dev->event_interface->wait); +} + void iio_device_unregister_eventset(struct iio_dev *indio_dev) { if (indio_dev->event_interface == NULL) -- 2.7.4