On Thu, 2017-09-07 at 19:17 -0700, Guenter Roeck wrote: > On 09/07/2017 07:06 PM, Andrew Jeffery wrote: > > On Thu, 2017-09-07 at 18:26 -0700, Guenter Roeck wrote: > > > On 09/07/2017 06:02 PM, Andrew Jeffery wrote: > > > > On Thu, 2017-09-07 at 17:27 -0700, Guenter Roeck wrote: > > > > > On 09/07/2017 08:22 AM, Andrew Jeffery wrote: > > > > > > On Thu, 2017-09-07 at 06:40 -0700, Guenter Roeck wrote: > > > > > > > On 09/06/2017 04:32 PM, Andrew Jeffery wrote: > > > > > > > > > > > > > > > > > > > > > > > > > Guess I need to dig up my eval board and see if I can > > > > > > > > > reproduce the problem. > > > > > > > > > Seems you are saying that the problem is always seen when > > > > > > > > > issuing a sequence > > > > > > > > > of "clear faults" commands on multiple pages ? > > > > > > > > > > > > > > > > Yeah. We're also seeing bad behaviour under other command > > > > > > > > sequences as well, > > > > > > > > which lead to this hack of a work-around patch[1]. > > > > > > > > > > > > > > > > I'd be very interested in the results of testing against the > > > > > > > > eval board. I > > > > > > > > don't have access to one and it seems Maxim have discontinued > > > > > > > > them. > > > > > > > > > > > > > > > > > > > > > > Do you have a somewhat reliable means to reproduce the problem ? > > > > > > > > > > > > It seems we hit a bunch of problems by just continually > > > > > > binding/unbinding the driver, if you don't apply that hacky oneshot > > > > > > retry patch. We can hit problems (in our design?) with something > > > > > > like: > > > > > > > > > > > > # cd /sys/bus/i2c/drivers/max31785; \ > > > > > > echo $addr > unbind; \ > > > > > > while echo $addr > bind; \ > > > > > > do echo $addr > unbind; echo -n .; done; > > > > > > > > > > > > It should hit issues covered by this patch, as the register checks > > > > > > are > > > > > > used in the operations used by probe. > > > > > > > > > > > > > > > > Hmm ... I didn't use your driver but my prototype driver which also > > > > > supports > > > > > temperature and voltage attributes, so if anything it should create > > > > > more > > > > > stress on the chip. > > > > > > > > I did add the temp and voltage attributes... > > > > > > > > Any chance you can give mine a try? I don't know what I would have done > > > > to invoke this kind of behaviour, so it would be useful to know whether > > > > or not it happens with one driver but not the other. > > > > > > > > > > Will do. > > > > Thanks. For reference, here's a devicetree description: > > > > https://github.com/openbmc/linux/blob/dev-4.10/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts#L283 > > > > I can't test with devicetree. x86 system. > > 2,100+ iterations with your driver, no failures.
Great. I really appreciate your testing here, so thanks for your efforts. I owe you a few drinks if we ever happen to meet. > > Either it is because my chip is a MAX31785 (not A), or the configuration > makes a difference, > or it is your hardware. Yep. My understanding is the A variant is just a difference of microcode, but who knows what affect that could have. > > I'll try to connect a couple of fans next (so far I did without) and try > again. Keep me posted if you do. Thanks again. Andrew > > Guenter
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