On 09/21/13 12:43, Lars-Peter Clausen wrote:
> 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.
Good point. I really ought to finish that input-iio driver sometime.
I keep hoping some keen person who actually has a use for it will pick
it up and do it for me :)
None of my boards have a screen so input devices aren't all that useful.
>
>> 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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