4 files changed, 21 insertions, 3 deletions

diff --git a/embassy-net/Cargo.toml b/embassy-net/Cargo.toml
index c64075b93..0f4571761 100644
--- a/embassy-net/Cargo.toml
+++ b/embassy-net/Cargo.toml
@@ -5,6 +5,7 @@ authors = ["Dario Nieuwenhuis <[email protected]>"]
 edition = "2018"
 
 [features]
+default = ["pool-4"]
 std = []
 defmt-trace = []
 defmt-debug = []
@@ -17,6 +18,11 @@ dhcpv4 = ["medium-ethernet", "smoltcp/socket-dhcpv4"]
 medium-ethernet = ["smoltcp/medium-ethernet"]
 medium-ip = ["smoltcp/medium-ip"]
 
+pool-4 = []
+pool-8 = []
+pool-16 = []
+pool-32 = []
+
 [dependencies]
 
 defmt = { version = "0.2.0", optional = true }
diff --git a/embassy-net/src/device.rs b/embassy-net/src/device.rs
index 5fcb94ac8..fc9d08947 100644
--- a/embassy-net/src/device.rs
+++ b/embassy-net/src/device.rs
@@ -43,8 +43,8 @@ impl<'a> SmolDevice<'a> for DeviceAdapter {
     type TxToken = TxToken<'a>;
 
     fn receive(&'a mut self) -> Option<(Self::RxToken, Self::TxToken)> {
+        let tx_pkt = PacketBox::new(Packet::new())?;
         let rx_pkt = self.device.receive()?;
-        let tx_pkt = PacketBox::new(Packet::new()).unwrap(); // TODO: not sure about unwrap
         let rx_token = RxToken { pkt: rx_pkt };
         let tx_token = TxToken {
             device: self.device,
diff --git a/embassy-net/src/lib.rs b/embassy-net/src/lib.rs
index 88dcf0aa5..51eb97a2e 100644
--- a/embassy-net/src/lib.rs
+++ b/embassy-net/src/lib.rs
@@ -13,7 +13,7 @@ pub use config::DhcpConfigurator;
 pub use config::{Config, Configurator, Event as ConfigEvent, StaticConfigurator};
 
 pub use device::{Device, LinkState};
-pub use packet_pool::{Packet, PacketBox, PacketBoxExt, PacketBuf};
+pub use packet_pool::{Packet, PacketBox, PacketBoxExt, PacketBuf, MTU};
 pub use stack::{init, is_config_up, is_init, is_link_up, run};
 
 #[cfg(feature = "tcp")]
diff --git a/embassy-net/src/packet_pool.rs b/embassy-net/src/packet_pool.rs
index 2c27d4013..b43ae2eb2 100644
--- a/embassy-net/src/packet_pool.rs
+++ b/embassy-net/src/packet_pool.rs
@@ -3,12 +3,24 @@ use core::ops::{Deref, DerefMut, Range};
 
 use atomic_pool::{pool, Box};
 
-pub const MTU: usize = 1514;
+pub const MTU: usize = 1516;
+
+#[cfg(feature = "pool-4")]
 pub const PACKET_POOL_SIZE: usize = 4;
 
+#[cfg(feature = "pool-8")]
+pub const PACKET_POOL_SIZE: usize = 8;
+
+#[cfg(feature = "pool-16")]
+pub const PACKET_POOL_SIZE: usize = 16;
+
+#[cfg(feature = "pool-32")]
+pub const PACKET_POOL_SIZE: usize = 32;
+
 pool!(pub PacketPool: [Packet; PACKET_POOL_SIZE]);
 pub type PacketBox = Box<PacketPool>;
 
+#[repr(align(4))]
 pub struct Packet(pub [u8; MTU]);
 
 impl Packet {