5 files changed, 32 insertions, 15 deletions
diff --git a/src/host/hcd.h b/src/host/hcd.h
index d5804c608..5547c7cc5 100644
--- a/src/host/hcd.h
+++ b/src/host/hcd.h
@@ -125,7 +125,7 @@ bool hcd_dcache_clean_invalidate(void const* addr, uint32_t data_size) TU_ATTR_W
 //--------------------------------------------------------------------+
 
 // optional hcd configuration, called by tuh_configure()
-bool hcd_configure(uint8_t rhport, uint32_t cfg_id, const void* cfg_param) TU_ATTR_WEAK;
+bool hcd_configure(uint8_t rhport, uint32_t cfg_id, const void* cfg_param);
 
 // Initialize controller to host mode
 bool hcd_init(uint8_t rhport);
diff --git a/src/host/usbh.c b/src/host/usbh.c
index 05091736e..aa0603d47 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -52,6 +52,13 @@ TU_ATTR_WEAK bool hcd_deinit(uint8_t rhport) {
   return false;
 }
 
+TU_ATTR_WEAK bool hcd_configure(uint8_t rhport, uint32_t cfg_id, const void* cfg_param) {
+  (void) rhport;
+  (void) cfg_id;
+  (void) cfg_param;
+  return false;
+}
+
 TU_ATTR_WEAK void tuh_event_hook_cb(uint8_t rhport, uint32_t eventid, bool in_isr) {
   (void) rhport;
   (void) eventid;
@@ -332,11 +339,7 @@ bool tuh_rhport_reset_bus(uint8_t rhport, bool active) {
 //--------------------------------------------------------------------+
 
 bool tuh_configure(uint8_t rhport, uint32_t cfg_id, const void *cfg_param) {
-  if ( hcd_configure ) {
-    return hcd_configure(rhport, cfg_id, cfg_param);
-  } else {
-    return false;
-  }
+  return hcd_configure(rhport, cfg_id, cfg_param);
 }
 
 static void clear_device(usbh_device_t* dev) {
diff --git a/src/host/usbh.h b/src/host/usbh.h
index 0e31e80a7..57362c778 100644
--- a/src/host/usbh.h
+++ b/src/host/usbh.h
@@ -73,11 +73,21 @@ typedef struct {
   tusb_desc_interface_t desc;
 } tuh_itf_info_t;
 
-// ConfigID for tuh_config()
+// ConfigID for tuh_configure()
 enum {
-  TUH_CFGID_RPI_PIO_USB_CONFIGURATION = OPT_MCU_RP2040 << 8 // cfg_param: pio_usb_configuration_t
+  TUH_CFGID_INVALID = 0,
+  TUH_CFGID_RPI_PIO_USB_CONFIGURATION = 100, // cfg_param: pio_usb_configuration_t
+  TUH_CFGID_MAX3421 = 200,
 };
 
+typedef union {
+  // For TUH_CFGID_RPI_PIO_USB_CONFIGURATION use pio_usb_configuration_t
+
+  struct {
+    uint8_t max_nak;
+  } max3421;
+} tuh_configure_param_t;
+
 //--------------------------------------------------------------------+
 // APPLICATION CALLBACK
 //--------------------------------------------------------------------+
diff --git a/src/portable/analog/max3421/hcd_max3421.c b/src/portable/analog/max3421/hcd_max3421.c
index 1b182e551..12d80e0b5 100644
--- a/src/portable/analog/max3421/hcd_max3421.c
+++ b/src/portable/analog/max3421/hcd_max3421.c
@@ -30,6 +30,7 @@
 
 #include <stdatomic.h>
 #include "host/hcd.h"
+#include "host/usbh.h"
 
 //--------------------------------------------------------------------+
 //
@@ -230,7 +231,9 @@ typedef struct {
 } max3421_data_t;
 
 static max3421_data_t _hcd_data;
-static uint8_t _max_nak = MAX_NAK_DEFAULT; // max NAK before giving up in a usb frame
+
+// max NAK before giving up in a frame. 0 means infinite NAKs
+static uint8_t _max_nak = MAX_NAK_DEFAULT;
 
 //--------------------------------------------------------------------+
 // API: SPI transfer with MAX3421E
@@ -409,10 +412,11 @@ static void free_ep(uint8_t daddr) {
   }
 }
 
-// Check if endpoint has an queued transfer
+// Check if endpoint has an queued transfer and not reach max NAK
 TU_ATTR_ALWAYS_INLINE static inline bool is_ep_pending(max3421_ep_t const * ep) {
   uint8_t const state = ep->state;
-  return ep->packet_size && state >= EP_STATE_ATTEMPT_1 && state < EP_STATE_ATTEMPT_1 + _max_nak;
+  return ep->packet_size && (state >= EP_STATE_ATTEMPT_1) &&
+         (_max_nak == 0 || state < EP_STATE_ATTEMPT_1 + _max_nak);
 }
 
 // Find the next pending endpoint using round-robin scheduling, starting from next endpoint.
@@ -447,10 +451,11 @@ static max3421_ep_t * find_next_pending_ep(max3421_ep_t * cur_ep) {
 // optional hcd configuration, called by tuh_configure()
 bool hcd_configure(uint8_t rhport, uint32_t cfg_id, const void* cfg_param) {
   (void) rhport;
-  (void) cfg_id;
-  (void) cfg_param;
+  TU_VERIFY(cfg_id == TUH_CFGID_MAX3421);
 
-  return false;
+  tuh_configure_param_t const* cfg = (tuh_configure_param_t const*) cfg_param;
+  _max_nak = cfg->max3421.max_nak;
+  return true;
 }
 
 // Initialize controller to host mode
diff --git a/src/tusb_option.h b/src/tusb_option.h
index f90fb7026..812074c44 100644
--- a/src/tusb_option.h
+++ b/src/tusb_option.h
@@ -144,7 +144,6 @@
 #define OPT_MCU_RX72N            1402 ///< Renesas RX72N
 #define OPT_MCU_RAXXX            1403 ///< Renesas RAxxx families
 
-
 // Mind Motion
 #define OPT_MCU_MM32F327X        1500 ///< Mind Motion MM32F327