defmt_rtt::flush implementation does not work with probe-rs

[Urhengulas]

I just realized that probe-rs does not set RTT to blocking, at least that is how I understand the documentation (link). While this is generally good, this means the defmt-rtt cannot detect that probe-rs is connected and therefore the flush implementation does not work anymore.

defmt/firmware/defmt-rtt/src/channel.rs

Lines 103 to 106 in ae2d0df

	fn host_is_connected(&self) -> bool {
	// we assume that a host is connected if we are in blocking-mode. this is what probe-run does.
	self.flags.load(Ordering::Relaxed) & MODE_MASK == MODE_BLOCK_IF_FULL
	}

Any ideas how to detect it otherwise?

[bugadani]

I think it's a clever enough idea and we can configure channels to blocking in probe-rs if we can prove they are defmt-related up channels.

[Urhengulas]

I think it's a clever enough idea and we can configure channels to blocking in probe-rs if we can prove they are defmt-related up channels.

That's a good idea