Have either of you seen any updates on fixes for this? I have done some searching and have not yet come up with anything that may fix the issue in any active kernel patches.
I am using a similar workaround to retry on failure, but am considering digging into this to fix the root cause. Zach On Sunday, August 25, 2013 7:09:21 AM UTC-5, Charles Steinkuehler wrote: > > I am having serious problems using multiple ADC channels in the latest > -bone26 kernel. When reading more than one ADC channel, you cannot read > more than 15 samples before getting an I/O error reading the AINx file > from sysfs (Resource temporarily unavailable). The read rate doesn't > matter, the problem appears to be related to switching between the > channels somehow. > > Can anyone else verify this issue? > > Who gets bug reports about the BeagleBone kernel patch set? This > doesn't quite seem appropriate for the OMAP kernel list, or is it? > > DETAILS TO REPRODUCE: > > I have a simplistic test script to reproduce this behavior, assuming you > have previously loaded the cape-bone-iio overlay: > > #/bin/sh > while : ; do > for ADC in AIN4 AIN5 ; do > echo -n "$ADC: " > cat /sys/devices/ocp.*/helper.*/$ADC > sleep 1 > done > done > > When you run this, after every 15 reads of AIN4, the system throws an > I/O error and the 16th read of AIN4 fails. At this point, things seem > to reset and you can read another 15 values before the next error. > > Example output: > > ... > AIN4: 589 > AIN5: 817 > AIN4: 586 > AIN5: 811 > AIN4: 588 > AIN5: 816 > AIN4: cat: /sys/devices/ocp.2/helper.12/AIN4: Resource temporarily > unavailable > AIN5: 997 > AIN4: 597 > AIN5: 1000 > AIN4: 595 > AIN5: 996 > AIN4: 595 > AIN5: 995 > AIN4: 598 > AIN5: 999 > AIN4: 595 > AIN5: 997 > AIN4: 594 > AIN5: 992 > AIN4: 597 > AIN5: 998 > AIN4: 595 > AIN5: 994 > AIN4: 597 > AIN5: 999 > AIN4: 595 > AIN5: 997 > AIN4: 594 > AIN5: 993 > AIN4: 598 > AIN5: 999 > AIN4: 595 > AIN5: 997 > AIN4: 595 > AIN5: 994 > AIN4: 598 > AIN5: 997 > AIN4: cat: /sys/devices/ocp.2/helper.12/AIN4: Resource temporarily > unavailable > AIN5: 994 > AIN4: 598 > ... > > -- > Charles Steinkuehler > [email protected] <javascript:> > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
