On 8/03/21 5:59 pm, Guenter Roeck wrote: > On 3/7/21 8:37 PM, Chris Packham wrote: > [ ... ] >>> That's from -ENXIO which is used in only one place in i2c-mpc.c. I'll >>> enable some debug and see what we get. >> For the errant readings there was nothing abnormal reported by the driver. >> >> For the "No such device or address" I saw "mpc-i2c ffe119000.i2c: No >> RXAK" which matches up with the -ENXIO return. >> > Id suggest to check the time until not busy and stop in mpc_xfer(). > Those hot loops are unusual, and may well mess up the code especially > if preempt is enabled. Reworking those loops seems to have had a positive result. I'll do a bit more testing and hopefully get a patch out later today. > Also, are you using interrupts or polling in > your system ? The interrupt handler looks a bit odd, with "Read again > to allow register to stabilise". > > Do you have fsl,timeout set in the devicetree properties and, if so, > have you played with it ? > > Other than that, the only other real idea I have would be to monitor > the i2c bus. > > Guenter