Hello, 
thank you for the answer and sorry for the late reply,
is it possible to disable the driver without recompiling the kernel?

I see there are 4 drivers present for the am335x:


kernel/drivers/pwm/pwm-tiecap.ko 
kernel/drivers/pwm/pwm-tiehrpwm.ko 
kernel/drivers/regulator/pwm-regulator.ko 
kernel/drivers/video/backlight/pwm_bl.ko

What's the difference between the first two?

The folder I assumed to be filled (/sys/class/pwm) when the drivers are 
enabled is empty. 

Also:
Does the kernel manages the timer and pwm with same driver?

Thank you,

-l


Il giorno venerdì 29 dicembre 2017 15:53:28 UTC+1, RobertCNelson ha scritto:
>
> On Fri, Dec 29, 2017 at 8:22 AM, Henner Zeller <[email protected] 
> <javascript:>> wrote: 
> > On 27 December 2017 at 13:48, Leonardo Romor <[email protected] 
> <javascript:>> wrote: 
> >> Hello, 
> >> 
> >> could someone explain me why running this code freezes the kernel? 
> >> 
> >> https://gist.github.com/lromor/e303c88cfb8a065d411f2ba0bc52324b 
> > 
> > Thanks Leonardo to measure and put together this report of this issue 
> > when using 4.4.91-ti-r137. 
> > 
> >> 
> >> It should turn on the beaglebone TIMER4. 
> >> I have tested this code on 3.8 kernel and it works. 
> > 
> > This currently prevents PWM to work in BeagleG in newer kernels; so it 
> > would be good to know from some of the people familiar with the 
> > kernel/GPIO interaction could chime in and explain what is going on 
> > and if there is a way to work-around it or if the initialization 
> > should be different altogether. 
>
> Let's see, your mmap'ing a clock that "was" being handled by the 
> kernel's pwm subsystem, and now the system freezes... 
>
> Well, stop mmap'ing or disable the pwm driver.. 
>
> Regards, 
>
> -- 
> Robert Nelson 
> https://rcn-ee.com/ 
>

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