Re: iio_trigger_poll_chained stop and trig->use_count always equals to 1

[Lars-Peter Clausen <lars@metafoo.de>]

On 07/16/2013 11:26 AM, Denis CIOCCA wrote:
> Hi all,
> 
> I need your help to understanding my strange issue...
> The scenario is that:
> 
> - I have one I2C device (microcontroller) that expose some sensors.
> - I wrote one driver that create one IIO device for each sensor.
> - There is only one trigger associated to all IIO devices, and one buffer for 
> each device.
> 
> When interrupt appear (DRDY of one or more sensors), the driver reads a mask 
> from micro to understand how many sensors have new data. After that, the 
> driver reads all new data from micro and save all data to one buffer. This is 
> done in a threaded irq function.
> 
> When iio_trigger_poll_chained is called, all data are saved to one common 
> buffer, each iio_triggered_buffer_setup functions is called and can split and 
> push their data to iio_buffer.
> 
> The issue is that: after some samples (about 50:100) the 
> iio_trigger_poll_chained doesn't call the iio_triggered_buffer_setup functions 
> and trig->use_count is always equals to 1.
> 

Yea, there is a race condition. Try this patch:
http://www.spinics.net/lists/linux-iio/msg08710.html

- Lars