5 Replies Latest reply on Mar 2, 2015 3:55 AM by motumeril

    mmal: Received unexpected camera control callback event, 0x4f525245


      Hi - I've bought a couple dozen raspberry pi cameras from you folks for a class I teach... Over the past couple of years I have gotten this error on over half of them:


      mmal: Received unexpected camera control callback event, 0x4f525245


      The kids absolutely love using the cameras, but It's getting pretty expensive to support the class by re-purchasing them. This appears to be a hot topic around the internet on RPi forums, and I have yet to hear a successful fix. Apparently this is tied to a conflict in resources in-board, from https://www.bountysource.com/issues/1335530-kernels-3-10-w1_gpio-destroys-i2c-bus-0-raspicam-doesn-t-work-anymore


      The problem is that the 1-wire module overwrite the gpio function selection for the I2C pins.
      Before 1-wire is loaded *0x20200000 = 0x48024 and I2C works (GPIO0 and GPIO in I2C alt function)
      After 1-wire is loaded *0x20200000 = 0x48921 and I2C fails (GPIO0 is set to an output)

      No idea yet why that happens yet, but that explains why I2C (and camera) stops working.


      I hate to stop using the camera with these pis (tried b, b+, A+ all have failed) but I don't know what else to do. Can you folks help?