From: simon.guinot@sequanux.org (Simon Guinot) Date: Wed, 19 Jun 2013 23:26:33 +0200 Subject: [RESEND,PATCHv6 1/1] Add support for GMT G762/G763 PWM fan controllers In-Reply-To: <20130619205321.GA7625@roeck-us.net> References: <87sj0jhuhn.fsf@natisbad.org> <20130617101948.GY7626@kw.sim.vm.gnt> <8761x9svpf.fsf@natisbad.org> <20130619205321.GA7625@roeck-us.net> Message-ID: <20130619212633.GC7626@kw.sim.vm.gnt> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jun 19, 2013 at 01:53:21PM -0700, Guenter Roeck wrote: > On Wed, Jun 19, 2013 at 10:15:56PM +0200, Arnaud Ebalard wrote: > > Hi Simon, > > > > Simon Guinot writes: > > > > > I have tested this patch on my 2Big Network v2 board. > > > > > > Sometimes I get a weird "No such device" error while reading or writing > > > the hwmon sysfs attributes. For example: > > > > > > # cat pwm1 > > > cat: read error: No such device > > > # cat pwm1 > > > 0 > > > This is odd, since ENODEV should not be returned as error code from i2c read > operations. > > What is the i2c controller ? The controller is the very same as for the ReadyNAS Duo v2. It is built in the Marvell Kirkwood SoC and the driver is i2c-mv64xxx. I will try an another board to see if I reproduce the error. Regards, Simon > > Thanks, > Guenter > > > Weird, I cannot reproduce that at all on my ReadyNAS Duo v2. > > > > > Note, that if the same command is executed again (just after the faulty > > > one), then it will succeed most of the time. The errors seems to happen > > > quite randomly and not very often. I'd say one time over ten tries. > > > I suppose this error is now visible due to the enhanced error path in > > > g762_update_client. It looks like we learn something by checking the > > > return value for i2c_smbus_read_byte_data :) > > > > > > Except that, all is working as expected. This new version fixes > > > effectively open-loop driving when the set_cnt register is set to 0xff. > > > > > > Also I am planning (hopefully this Wednesday) to test your patch on my > > > 5Big Network v2 board. This last also embed a g762 controller but with a > > > three wires fan instead. Then, I should be able to test the closed-loop > > > mode behaviour. > > > > Thanks for your tests, Simon. > > > > Cheers, > > > > a+ > > -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 198 bytes Desc: Digital signature URL: