Char device write repeating

[François]

On Tue, Oct 04, 2016 at 03:42:52PM -0300, Daniel. wrote:
> Because the libc is calling it again based on what has been passed as
> argument and what was received as return value. Here is one example
> https://gist.github.com/gkos/5479135. I don't really know if this code is
> working since I made it a long time ago.

Your test to check wether the device is already open looks weak to me.
You should rather use atomic operations such as described in [1] or
mutex like in [2].

[1] http://www.oreilly.com/openbook/linuxdrive3/book/ch06.pdf p 40
[2] http://pete.akeo.ie/2011/08/writing-linux-device-driver-for-kernels.html

-- 
François