On 09/21/2013 01:56 PM, Jonathan Cameron wrote:
On 09/18/13 21:02, Lars-Peter Clausen wrote:
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 <lars@xxxxxxxxxx>
This is probably the only one in the set that isn't technically a 'fix' so could you
reorder so this is at the end. I'll then push it out once one the other patches
have made there way into the staging-next tree.
While the last two patches are fixes, there is currently no way to trigger the
bug they fix since there are no users of the cb_buffer yet, so strictly
speaking they don't have to go into the fixes branch.
Thanks,
---
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 e9cbde3..c28625a 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -20,6 +20,7 @@
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/poll.h>
+#include <linux/sched.h>
#include <linux/iio/iio.h>
#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 dd7b601..88a77d9 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1140,6 +1140,10 @@ 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 3843abf..6aace88 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 */
}
@@ -455,6 +460,20 @@ 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)
--
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