title: Unable to change gpio value
body: <p>Currently I'm trying to check the booting time of an Tixi board using systemd on a 2.6.39 linux kernel. To do so I created a service file that calls a bash script which sets and uses a gpio. The problem is that my systems is not allowing me to change the value of the gpio. I can sucessfully export it, change its direction, but NOT the value. I have connected an oscilloscope to check if the value had changed in the hardware but not updated in the file as suggested in some forums, but it was the same: the value just doesn't change!
  I should also point out that the same script is working if I use system V, with exactly the same coonfiguration for the kernel, busybox and filesystem.</p>
  
  <p>It is very ironic because I'm already the root of the systems, nevertheless even changing the permissions of the file, would not allow me to change its value. There is also no feedback from the kernel saying that the operation was not possible, but rather it looks as if it was possible but when I check the value, it was the same as before.</p>
  
  <p>I also tried to run that in the Raspbian with a 3.12 (which I changed to systemd) and it was in fact possible to do it, just in the normal way from userspace. </p>
  
  <p>I would appreciate if you have any idea oh what might be the problem since I already run out of ideas.</p>
  
  <p>Thanks</p>
  
  <p>PS: This is the code that should work on the bash line:</p>
  
  <pre><code>echo 0 &gt; /sys/class/gpio/gpio104/value
  more /sys/class/gpio/gpio104/value
  // I get 1 not 0 as I requested
  </code></pre>
  
  <p>Nevertheless the same lines of code in the same board work if I use systemV but not if I use systemd</p>