From 59c2778418f847e76170c8d91a7ab4e1045fda31 Mon Sep 17 00:00:00 2001
From: Adam Greig <adam@adamgreig.com>
Date: Sat, 6 Jun 2026 18:00:22 +0100
Subject: [PATCH] Add eth-packet-trace feature that cfg-gates the logging at
 ethernet packet reception/transmission

---
 firmware/zynq7000-hal/Cargo.toml         |  4 ++++
 firmware/zynq7000-hal/src/eth/smoltcp.rs | 11 ++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/firmware/zynq7000-hal/Cargo.toml b/firmware/zynq7000-hal/Cargo.toml
index 7883c56..b68be84 100644
--- a/firmware/zynq7000-hal/Cargo.toml
+++ b/firmware/zynq7000-hal/Cargo.toml
@@ -65,6 +65,10 @@ time-driver-gtc = ["dep:embassy-time-driver", "dep:embassy-time-queue-utils", "d
 # caching is disabled.
 eth-cache-maintenance = []
 
+# Enable debug-level (packet size only) and trace-level (packet contents)
+# logging of all packets received and transmitted.
+eth-packet-trace = []
+
 [dev-dependencies]
 approx = "0.5"
 
diff --git a/firmware/zynq7000-hal/src/eth/smoltcp.rs b/firmware/zynq7000-hal/src/eth/smoltcp.rs
index cc15473..9b0c655 100644
--- a/firmware/zynq7000-hal/src/eth/smoltcp.rs
+++ b/firmware/zynq7000-hal/src/eth/smoltcp.rs
@@ -53,7 +53,9 @@ impl SmoltcpRxToken<'_> {
         invalidate_data_cache_range(self.rx_buf.0.as_ptr() as u32, clean_invalidate_len)
             .expect("RX buffer or buffer size not aligned to cache line size");
 
+        #[cfg(feature = "eth-packet-trace")]
         log::debug!("eth rx {} bytes", self.rx_size);
+        #[cfg(feature = "eth-packet-trace")]
         log::trace!("rx data: {:x?}", &self.rx_buf.0[0..self.rx_size]);
         let result = f(&mut self.rx_buf.0[0..self.rx_size]);
         self.descr_list.clear_slot(self.slot_index);
@@ -112,7 +114,9 @@ impl SmoltcpTxToken<'_> {
         clean_and_invalidate_data_cache_range(buffer.0.as_ptr() as u32, clean_invalidate_len)
             .expect("TX buffer or buffer size not aligned to cache line size");
 
+        #[cfg(feature = "eth-packet-trace")]
         log::debug!("eth tx {len} bytes");
+        #[cfg(feature = "eth-packet-trace")]
         log::trace!("tx data: {:x?}", &buffer.0[0..len]);
         self.descr_list
             .prepare_transfer_unchecked(Some(addr), u14::new(len as u16), true, false);
@@ -255,12 +259,13 @@ impl CommonSmoltcpDriver {
             rx_descr::FrameScanResult::SingleFrame {
                 index,
                 size,
-                status,
+                status: _status,
             } => {
+                #[cfg(feature = "eth-packet-trace")]
                 log::trace!(
                     "eth rx frame, fsc status {:?}, cksum status {:?}",
-                    status.fcs_status(),
-                    status.type_id_match_info_or_chksum_status()
+                    _status.fcs_status(),
+                    _status.type_id_match_info_or_chksum_status()
                 );
 
                 let rx_buf = self.bufs.rx_bufs.get_mut(index).unwrap();