Hi Guenter, Sorry my blunder mistake. Sorry for the noise. I just tested with spiking this patch and my observation and testing were wrong we can skip this patch. I will send an v2 patch series removing the patch 5 and patch 6. With correct dts changes. Thanks for pointing my mistake. -Anand Moon On 8 April 2015 at 22:23, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > On Wed, Apr 08, 2015 at 09:32:05PM +0530, Anand Moon wrote: >> Hi Guenter, >> >> Initially the board bootup the cooling level state is 0. >> So update the duty cycle and this power off the fan. >> As their is no state change the fan will not spin. >> >> Once the temperature sensor is reached to alert temperature it changes state. >> With the state change the fan cools the CPU and then stop's >> >> I have observed this state change with tmon utility in linux/tools/thermal/tmon/ >> > Sorry, I am missing something. I still don't see what problem you are fixing > with this patch. What behavior is wrong with the current code, and how does your > patch fix it ? > > Guenter > >> -Anand Moon >> >> On 8 April 2015 at 21:02, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: >> > On Wed, Apr 08, 2015 at 10:44:15AM +0200, Lukasz Majewski wrote: >> >> Hi Anand, >> >> >> >> > Below changes depend on following patch. >> >> > https://patchwork.kernel.org/patch/5944061/ >> >> > >> >> > Update the pwm_config with duty then update the pwm_disable >> >> > to poweroff the cpu fan. >> >> > >> > >> > Unfortunately, the patch does not include an explanation why it is needed. >> > >> > The original code presumably did not update the duty cycle because >> > pwm was about to be disabled anyway. That kind of made sense to me. >> > Updating the duty cycle to 0 just to disable the pwm channel right >> > afterwards does not immediately make sense. >> > >> > Given that, I would expect to see a rationale here. Why is this patch needed ? >> > Does it fix a bug ? If yes, pelase describe the bug. If not, what is the >> > purpose of this patch ? >> > >> > Maybe that is all explained in patch 0/6, which I was not copied on. Even >> > if so, the reationale will be needed in the changelog to explain to future >> > developers why this change was made. >> > >> > Thanks, >> > Guenter >> > >> >> > Tested on OdroidXU3 board. >> >> > >> >> > Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx> >> >> > --- >> >> > drivers/hwmon/pwm-fan.c | 10 ++++------ >> >> > 1 file changed, 4 insertions(+), 6 deletions(-) >> >> > >> >> > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c >> >> > index 7c83dc4..f25c841 100644 >> >> > --- a/drivers/hwmon/pwm-fan.c >> >> > +++ b/drivers/hwmon/pwm-fan.c >> >> > @@ -44,26 +44,24 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, >> >> > unsigned long pwm) int ret = 0; >> >> > >> >> > mutex_lock(&ctx->lock); >> >> > + >> > >> > [ please refrain from unnecessary whitespace changes ] >> > >> >> > if (ctx->pwm_value == pwm) >> >> > goto exit_set_pwm_err; >> >> > >> >> > - if (pwm == 0) { >> >> > - pwm_disable(ctx->pwm); >> >> > - goto exit_set_pwm; >> >> > - } >> >> > - >> >> > duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM); >> >> > ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); >> >> > if (ret) >> >> > goto exit_set_pwm_err; >> >> > >> >> > + if (pwm == 0) >> >> > + pwm_disable(ctx->pwm); >> >> > + >> >> > if (ctx->pwm_value == 0) { >> >> > ret = pwm_enable(ctx->pwm); >> >> > if (ret) >> >> > goto exit_set_pwm_err; >> >> > } >> >> > >> >> > -exit_set_pwm: >> >> > ctx->pwm_value = pwm; >> >> > exit_set_pwm_err: >> >> > mutex_unlock(&ctx->lock); >> >> >> >> Reviewed-by: Lukasz Majewski <l.majewski@xxxxxxxxxxx> >> >> >> >> BTW: I've added Guenter to CC. >> >> >> >> -- >> >> Best regards, >> >> >> >> Lukasz Majewski >> >> >> >> Samsung R&D Institute Poland (SRPOL) | Linux Platform Group -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
