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duskglow

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  1. Hi Tony, thanks. I can make a small program that will trigger this issue this weekend, I had to cannibalize the card for the rpi 3 because the project must go on, but new cards are arriving this weekend. I will say that I discovered more, though. It's a gpxx potato, apparently there are a few different kinds. I also managed to track the fault across kernel boundaries and right into kernel space. The EINVAL is coming from the GPIO_V2_GET_LINE_IOCTL ioctl, and while I don't understand exactly how it works, the problem *seems* to be that the GPIO22 (chip 0, offset 10, header pin 15) line is also the TEST_N line, and for some reason this line is in a different bank than the kernel pinctrl code is expecting. I think this is true *only* for this particular line, and while it won't get in the way of most people, the adafruit hat uses this line, so it's kind of impossible to make that work properly at the moment (I actually made some really good progress at getting the rpi-rgb-led-matrix software to work using gpiod, but this is not surmountable at the present time.) If this is not enough info, check back Sat. or Sun., I will post a small proof of concept program that will just exercise that line. Thanks for getting back.
  2. Not sure if this is beginner or advanced, so I guess I'll start here. I have a "le potato" I recently bought. Getting it working has been a nightmare, but I'm almost there. Right now my project is to get a 32x64 RGB matrix working using an adafruit hat. I got Armbian 22.02.1 Focal running on it, and I'm using the gpiod library. I've had to write my own access library, but I've almost got it working, translating the pin labels ("7J1 Header Pin15") to the appropriate GPIO/offset values for use with gpiod. Except for exactly one. I try to use request_line on GPIO 22 (chip 0, offset 10) and it gives me an invalid argument. Doesn't do this for any other GPIO and I'm at my wit's end. I see in the docs that this is a "TEST_N" pin with a double asterisk notation that it needs a recent kernel to set output, but mine is plenty recent enough. I've also verified triply that I'm trying to access gpiochip0, offset 10. Some info that might be valuable. Virtual cookies if you can help. Thanks.,
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