No way to use pin for pwm after calling SetPinMode.

[007roy]

Describe the bug
On Raspberry Pi 4
If GpioController.SetPinMode or OpenPin are used to set PinMode.Output at anytime system must be rebooted before PwmChannel can be used.

Steps to reproduce
Add 'dtoverlay=pwm,pin=18,func=2' line to /boot/config.txt and reboot

exec this code:
...
var pwm=PwmChannel.Create(0,0,500,1);
pwm.start();
...

exec this code:
...
controller.OpenPin(18,PinMode.Output);
...

then repeat:
...
var pwm=PwmChannel.Create(0,0,500,1);
pwm.start();
...

Expected behavior

Describe what did you expect to happen

Actual behavior

Describe what actually happened

Versions used

Add following information:

.NET SDK (reflecting any global.json):
Version: 5.0.100
Commit: 5044b93829

Runtime Environment:
OS Name: raspbian
OS Version: 10
OS Platform: Linux
RID: linux-arm
Base Path: /home/pi/dotnet/sdk/5.0.100/

Host (useful for support):
Version: 5.0.0
Commit: cf258a14b7

.NET SDKs installed:
5.0.100 [/home/pi/dotnet/sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 5.0.0 [/home/pi/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 5.0.0 [/home/pi/dotnet/shared/Microsoft.NETCore.App]

[pgrawehr]

Hi @007roy

This is a known problem, see #874, #878 and others. If you've got wiringpi installed (the latest version), you can use a command like gpio -g mode 12 ALT0 to reset pin 12 to PWM.

PR #1128 is going to fix this. Since it's a big change, review is taking its time. But we definitelly want this in the next release.

[krwq]

@007roy thank you for filing the issue - this gives us feel that this is not a potential problem happening with tests abusing the APIs and it's an actual pain point. Just to clarify: next release => next major release timeline. This is something we do want to ship but it has non-trivial design - getting this wrong would have really bad long-term user experience impact which we'd prefer to avoid and that's why we prefer to take extra time on the APIs.

[ghost]

This issue has been marked as duplicate and has not had any activity for 1 day. It will be closed for housekeeping purposes.

[ghost]

This issue has been marked as duplicate and has not had any activity for 1 day. It will be closed for housekeeping purposes.