StreamOut() hangs for ever

[stackcoder]

Describe the bug
I wanted to use the gpiomem feature to get at least reasonably correct timings for my gpio.

To Reproduce
Steps to reproduce the behavior:

1. Take the gpiostream PinOut example code, remove (since it's not implemented) stream and program wrapper

package main

import (
	"log"

	"periph.io/x/conn/v3/gpio/gpioreg"
	"periph.io/x/conn/v3/gpio/gpiostream"
	"periph.io/x/conn/v3/physic"
	"periph.io/x/host/v3"
)

func main() {
	state, err := host.Init()
	if err != nil {
		log.Fatalf("failed to initialize periph: %v", err)
	}

	log.Printf("Drivers failed to load:\n")
	for _, failure := range state.Failed {
		log.Printf("- %s: %v\n", failure.D, failure.Err)
	}

	p := gpioreg.ByName("GPIO24")
	r, ok := p.(gpiostream.PinOut)
	if !ok {
		log.Fatalf("pin streaming is not supported on pin %s", p)
	}
	b := gpiostream.BitStream{
		Freq: 1000 * physic.Hertz,
		Bits: []byte{0b1010_1010, 0b1100_1100},
	}
	if err := r.StreamOut(&b); err != nil {
		log.Fatal(err)
	}
}

2. Run it.
3. Process hangs forever
4. Get stack traces using kill -QUIT

SIGQUIT: quit
PC=0x1274bc m=0 sigcode=0

goroutine 1 gp=0x2002128 m=0 mp=0x2902d8 [running]:
periph.io/x/host/v3/bcm283x.(*dmaChannel).wait(...)
        /go/pkg/mod/github.com/stackcoder/periph-host/v3@v3.0.0-20260302180128-52e941200513/bcm283x/dma.go:563
periph.io/x/host/v3/bcm283x.runIO({0x1c19c4, 0x2012728}, 0x1)
        /go/pkg/mod/github.com/stackcoder/periph-host/v3@v3.0.0-20260302180128-52e941200513/bcm283x/dma.go:668 +0x138 fp=0x20b7e70 sp=0x20b7e28 pc=0x1274bc
periph.io/x/host/v3/bcm283x.dmaWriteStreamEdges(0x28c578, {0x1c1898, 0x205c888})
        /go/pkg/mod/github.com/stackcoder/periph-host/v3@v3.0.0-20260302180128-52e941200513/bcm283x/dma.go:975 +0x670 fp=0x20b7ef8 sp=0x20b7e70 pc=0x1289c4
periph.io/x/host/v3/bcm283x.(*Pin).StreamOut(0x28c578, {0x1c1898, 0x205c888})
        /go/pkg/mod/github.com/stackcoder/periph-host/v3@v3.0.0-20260302180128-52e941200513/bcm283x/gpio.go:734 +0x180 fp=0x20b7f28 sp=0x20b7ef8 pc=0x129a98
main.main()
        /workspaces/test/fail.go:32 +0x2f8 fp=0x20b7fa8 sp=0x20b7f28 pc=0x151c50
runtime.main()
        /usr/local/go/src/runtime/proc.go:285 +0x2f0 fp=0x20b7fec sp=0x20b7fa8 pc=0x5b180
runtime.goexit({})
        /usr/local/go/src/runtime/asm_arm.s:877 +0x4 fp=0x20b7fec sp=0x20b7fec pc=0x98180

goroutine 2 gp=0x20026c8 m=nil [force gc (idle)]:
runtime.gopark(0x19ab50, 0x28f628, 0x11, 0xa, 0x1)
        /usr/local/go/src/runtime/proc.go:460 +0x104 fp=0x202cfd4 sp=0x202cfc0 pc=0x92318
runtime.goparkunlock(...)
        /usr/local/go/src/runtime/proc.go:466
runtime.forcegchelper()
        /usr/local/go/src/runtime/proc.go:373 +0xe4 fp=0x202cfec sp=0x202cfd4 pc=0x5b5e4
runtime.goexit({})
        /usr/local/go/src/runtime/asm_arm.s:877 +0x4 fp=0x202cfec sp=0x202cfec pc=0x98180
created by runtime.init.6 in goroutine 1
        /usr/local/go/src/runtime/proc.go:361 +0x1c

goroutine 3 gp=0x20027e8 m=nil [GC sweep wait]:
runtime.gopark(0x19ab50, 0x28f788, 0xc, 0x9, 0x1)
        /usr/local/go/src/runtime/proc.go:460 +0x104 fp=0x202d7c4 sp=0x202d7b0 pc=0x92318
runtime.goparkunlock(...)
        /usr/local/go/src/runtime/proc.go:466
runtime.bgsweep(0x204a000)
        /usr/local/go/src/runtime/mgcsweep.go:279 +0xa8 fp=0x202d7e4 sp=0x202d7c4 pc=0x44da0
runtime.gcenable.gowrap1()
        /usr/local/go/src/runtime/mgc.go:212 +0x28 fp=0x202d7ec sp=0x202d7e4 pc=0x346a8
runtime.goexit({})
        /usr/local/go/src/runtime/asm_arm.s:877 +0x4 fp=0x202d7ec sp=0x202d7ec pc=0x98180
created by runtime.gcenable in goroutine 1
        /usr/local/go/src/runtime/mgc.go:212 +0x74

goroutine 4 gp=0x2002908 m=nil [GC scavenge wait]:
runtime.gopark(0x19ab50, 0x28f988, 0xd, 0xa, 0x2)
        /usr/local/go/src/runtime/proc.go:460 +0x104 fp=0x202dfb4 sp=0x202dfa0 pc=0x92318
runtime.goparkunlock(...)
        /usr/local/go/src/runtime/proc.go:466
runtime.(*scavengerState).park(0x28f988)
        /usr/local/go/src/runtime/mgcscavenge.go:425 +0x68 fp=0x202dfc8 sp=0x202dfb4 pc=0x421b0
runtime.bgscavenge(0x204a000)
        /usr/local/go/src/runtime/mgcscavenge.go:653 +0x3c fp=0x202dfe4 sp=0x202dfc8 pc=0x428d0
runtime.gcenable.gowrap2()
        /usr/local/go/src/runtime/mgc.go:213 +0x28 fp=0x202dfec sp=0x202dfe4 pc=0x34654
runtime.goexit({})
        /usr/local/go/src/runtime/asm_arm.s:877 +0x4 fp=0x202dfec sp=0x202dfec pc=0x98180
created by runtime.gcenable in goroutine 1
        /usr/local/go/src/runtime/mgc.go:213 +0xbc

goroutine 5 gp=0x2002a28 m=nil [GOMAXPROCS updater (idle)]:
runtime.gopark(0x19ab50, 0x28f758, 0x12, 0xa, 0x1)

Expected behavior
Well, I have been warned: "This package is still in flux as development is on-going."
Would wish to find my way to at least reasonably correct gpio timings.

Any ideas how to debug further?

Platform:

• OS: gokrazy
• Kernel: custom 6.12.62, based on raspberrypi official
• Board: Raspberry Pi 1 B+

Additional context
I needed to patch the library to get as far as that, see: #73