The problem disapears when I run the custom patched kernel with removed i2c bus 2 initialization. In this case there is no "Bus error" message and my test program works just fine. So I conclude that it was indeed some kind of conflict between kernel and my code trying to talk directly to the i2c controller.
Once again thank you Gilles for prompt response and suggestions! Regards, Andrey. On Sun, Jun 19, 2011 at 6:57 PM, Gilles Chanteperdrix <[email protected]> wrote: > On 06/19/2011 04:21 PM, Andrey Nechypurenko wrote: >>>> The module works. I think kernel configured it properly because I can >>>> use user space utility for example i2cdetect and see my sensors >>>> detected on the bus. At the moment where I was trying to read the >>>> status I did not made any reconfiguration before. So my assumption was >>>> that the module is already configured properly and at least an attempt >>>> to read the status should succede. >>> >>> To be sure of that, you would have to be sure that the clocks are not >>> disabled when the device is not opened. To check this, either check the >>> kernel sources, or try and open the i2c device, and keep it open before >>> you mmap /dev/mem >> >> Just tried your suggestion but unfortunately it does not change enything. >> > > There may be (at least) two possible reasons: > - the clocks are disabled, you need to check the kernel source to know > if that is the case; > - or the compiler generated a byte access to the 32 bits register, not > knowing the alignment of mmap return value, you need to send the > disassembly as I requested to know if that is the case. > > -- > Gilles. > _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
