diff --git a/embassy-stm32/src/eth/generic_smi.rs b/embassy-stm32/src/eth/generic_smi.rs
index 41d19e921..239c52634 100644
--- a/embassy-stm32/src/eth/generic_smi.rs
+++ b/embassy-stm32/src/eth/generic_smi.rs
@@ -3,7 +3,7 @@
 use core::task::Context;
 
 #[cfg(feature = "time")]
-use embassy_time::{Delay, Duration, Timer};
+use embassy_time::{Duration, Timer};
 #[cfg(feature = "time")]
 use futures_util::FutureExt;
 
@@ -52,20 +52,46 @@ pub struct GenericSMI {
 impl GenericSMI {
     /// Construct the PHY. It assumes the address `phy_addr` in the SMI communication
     ///
-    /// Set `phy_addr` to `0xFF` for automatic detection (only with `time` feature enabled)
+    /// # Panics
+    /// `phy_addr` must be in range `0..32`
     pub fn new(phy_addr: u8) -> Self {
+        assert!(phy_addr < 32);
         Self {
             phy_addr,
             #[cfg(feature = "time")]
             poll_interval: Duration::from_millis(500),
         }
     }
+
+    /// Construct the PHY. Try to probe all addresses from 0 to 31 during initialization
+    ///
+    /// # Panics
+    /// Initialization panics if PHY didn't respond on any address
+    pub fn new_auto() -> Self {
+        Self {
+            phy_addr: 0xFF,
+            #[cfg(feature = "time")]
+            poll_interval: Duration::from_millis(500),
+        }
+    }
+}
+
+// TODO: Factor out to shared functionality
+fn blocking_delay_us(us: u32) {
+    #[cfg(feature = "time")]
+    embassy_time::block_for(Duration::from_micros(us as u64));
+    #[cfg(not(feature = "time"))]
+    {
+        let freq = unsafe { crate::rcc::get_freqs() }.sys.to_hertz().unwrap().0 as u64;
+        let us = us as u64;
+        let cycles = freq * us / 1_000_000;
+        cortex_m::asm::delay(cycles as u32);
+    }
 }
 
 unsafe impl PHY for GenericSMI {
     fn phy_reset<S: StationManagement>(&mut self, sm: &mut S) {
         // Detect SMI address
-        #[cfg(feature = "time")]
         if self.phy_addr == 0xFF {
             for addr in 0..32 {
                 sm.smi_write(addr, PHY_REG_BCR, PHY_REG_BCR_RESET);
@@ -75,7 +101,8 @@ unsafe impl PHY for GenericSMI {
                         self.phy_addr = addr;
                         return;
                     }
-                    embedded_hal_1::delay::DelayNs::delay_us(&mut Delay, 1000);
+                    // Give PHY a total of 100ms to respond
+                    blocking_delay_us(10000);
                 }
             }
             panic!("PHY did not respond");