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Volkmer wrote: >>>> Thanks for CC'ing me on this thread. >>>> >>>> On 07/01/26 15:21, Uwe Kleine-König wrote: >>>>> adding Rafael to Cc: who sent a patch series for this driver that I >>>>> didn't come around to review yet. Given that neither he nor me >>>>> noticed >>>>> the problem addressed in this patch I wonder if it applies to all >>>>> hardware variants. >>>>> >>>> >>>> I also didn't observe the issue described here in my testing: duty >>>> cycle and >>>> period changes always appeared to take effect as expected. >>>> >>>> My tests were done on an AM623 EVM. >>>> >>>> One possible explanation is that my test flow mostly exercised >>>> configuration >>>> while the PWM was already enabled/active, which could mask the >>>> effect of a >>>> put_sync/reset happening after configuration. >>>> >>> >>> Yes, this is the reason why the configuration was taking effect for >>> you , >>> Rafael, as the PWM was already enabled when setting the >>> configuration hence >>> masking the effect of a put_sync/reset happening after configuration. >> >> Can you provide a list of commands that show the failure? That would >> result in less guessing for me. My plan is to reproduce the failure >> tomorrow to better understand it on my boneblack. >> >> Best regards >> Uwe > > Sure Uwe. These are the commands I have tried for PWM signal generation: > > cd /sys/class/pwm/pwmchip0 > /sys/class/pwm/pwmchip0# echo 0 > export > /sys/class/pwm/pwmchip0# cd pwm0/ > /sys/class/pwm/pwmchip0/pwm0# echo 10000000 > period > /sys/class/pwm/pwmchip0/pwm0# echo 3000000 > duty_cycle > /sys/class/pwm/pwmchip0/pwm0# echo "normal" > polarity > /sys/class/pwm/pwmchip0/pwm0# echo 1 > enable > > Once these commands were executed, I measured the PWM signal using > logic analyzer and the duty cycle was 100% even though we had set 30% > duty cycle through the sysfs nodes. > > However, with the below command sequence, the duty cycle was getting > set properly > > cd /sys/class/pwm/pwmchip0 > /sys/class/pwm/pwmchip0# echo 0 > export > /sys/class/pwm/pwmchip0# cd pwm0/ > /sys/class/pwm/pwmchip0/pwm0# echo 10000000 > period > /sys/class/pwm/pwmchip0/pwm0# echo 3000000 > duty_cycle > /sys/class/pwm/pwmchip0/pwm0# echo "normal" > polarity > /sys/class/pwm/pwmchip0/pwm0# echo 1 > enable > /sys/class/pwm/pwmchip0/pwm0# echo 3000000 > duty_cycle I don't think , this last call of setting duty_cycle , even will land in driver code . > > > PWM is working only if we re-update the duty cycle after enabling the > module. > > If we do not re-update the duty cycle after enabling the module then > PWM signal line is being high(100 % duty) always. > > Test Environment: TI J784S4 EVM board. > > Best Regards > Gokul Praveen > > >