Bug in pio/uart_rx /uart_rx_intr.c

[mxyxbb]

The function irq_get_exclusive_handler return NULL if pio_irqcan not be get. And then pio_irq++; will not be run.

if (irq_get_exclusive_handler(pio_irq)) {
        pio_irq++;
        if (irq_get_exclusive_handler(pio_irq)) {
            panic("All IRQs are in use");
        }
    }

https://github.com/raspberrypi/pico-examples/blob/eca13acf57916a0bd5961028314006983894fc84/pio/uart_rx/uart_rx_intr.c#L136C1-L142C1

[peterharperuk]

I think you're misinterpreting what the code is doing. It's checking if there is an irq without an exclusive handler. So if the first call to irq_get_exclusive_handler indicates that there's an exclusive handler, it checks the next irq. If they both return non-null then there are no free irqs. If irq_get_exclusive_handler return NULL then there's no handler and the code is free to use it. At the end of the code snippet pio_irq is the number of a free irq.

[mxyxbb]

if I call function stdio_init_all() many times, it will fill up shared irq slots in rp2040 mcu.

If it is possible to offer a stdio_deinit_all funtion?

assertion "irq_hander_chain_free_slot_head >= 0" failed: file "H:\shared_files\pico\pico-sdk\src\rp2_common\hardware_irq\irq.c", line 215, function: irq_add_shared_handler

[lurch]

if I call function stdio_init_all() many times, it will fill up shared irq slots in rp2040 mcu.

Why are you calling that function multiple times? I believe the intention is that you'd normally call it just once, when your program first starts up.

Looking at the Pico SDK API documentation in general (e.g. Hardware APIs or High Level APIs ), there appear to be many more _init functions than there are _deinit functions.

[mxyxbb]

Since I want to printf some information before and after I overclock the rp2040, may I initialize the stdio again as the sys clock has been changed? If I initialize it only once before I overclock the chip, uart baudrate will go wrong after the overclock. If I initialize it only once after I overclock the chip, printf info will not be visiable before the overclock. If I initialize it twice before and after I overclock the chip, the init func will fill up shared irq slots in rp2040 mcu, which cause no shared irq can be used in my user function.

[lurch]

In that case you should probably create a new issue in the pico-sdk repo, rather than continuing to discuss things on an already-closed issue in the pico-examples repo :wink:

[peterharperuk]

https://github.com/raspberrypi/pico-sdk/issues/1688