Reinstate alloc lock, clean read loop

src/allocator.rs

···
     ptr::NonNull,
 };
 
-use embassy_sync::blocking_mutex::{Mutex, raw::CriticalSectionRawMutex};
+use embassy_sync::blocking_mutex::Mutex;
 use rlsf::Tlsf;
 use static_cell::ConstStaticCell;
+
+use crate::locks::AllocatorLock;
 
 type Heap = Tlsf<'static, usize, usize, { usize::BITS as usize }, { usize::BITS as usize }>;
 
···
 }
 
 pub struct PicoHeap<const MEMORY_SIZE: usize> {
-    inner: Mutex<CriticalSectionRawMutex, HeapInner>,
+    inner: Mutex<AllocatorLock, HeapInner>,
     block: ConstStaticCell<[u8; MEMORY_SIZE]>,
 }
 

src/locks.rs

···
 use embassy_rp::spinlock_mutex::SpinlockRawMutex;
 
+pub type AllocatorLock = SpinlockRawMutex<0>;
 pub type RtcLock = SpinlockRawMutex<1>;
 pub type ConnectionStatusLock = SpinlockRawMutex<2>;
 pub type DataTransferLock = SpinlockRawMutex<3>;

src/net/crypto.rs

···
 use embassy_futures::select::{Either, select};
 use embassy_net::tcp::{TcpReader, TcpSocket, TcpWriter};
 use embedded_io_async::{Read, Write};
-use sachy_fmt::{error, unwrap, warn};
+use sachy_fmt::{error, unwrap};
 use striker_proto::{Server, ServerBuilder, ServerReceiver, ServerSender};
 
 use crate::{
···
                 .await
                 .map_err(|_| PicoError::CryptoProtoError)?;
 
-            if msg_size > 0
-                && let Ok(req) = recv_state.decode_request(&mut msg_buf)
+            let req = recv_state.decode_request(&mut msg_buf)?;
+
+            if let Some((resp, resp_tx)) = RpcServer::handle_request(req)
+                .await
+                .zip(UpdateConnection::can_update())
             {
-                let Some((resp, resp_tx)) = RpcServer::handle_request(req)
-                    .await
-                    .zip(UpdateConnection::can_update())
-                else {
-                    warn!("Connection dropped before response");
-                    break;
-                };
                 resp_tx.try_send(resp).ok();
+            } else {
+                break;
             }
 
             msg_buf.resize_with(4096, Default::default);