diff --git a/port/dwc2/usb_glue_esp.c b/port/dwc2/usb_glue_esp.c
index 6ce03857..03110fb8 100644
--- a/port/dwc2/usb_glue_esp.c
+++ b/port/dwc2/usb_glue_esp.c
@@ -144,6 +144,7 @@ void usb_dc_low_level_init(uint8_t busid)
 {
     esp_err_t ret;
     void *reg_base = (void*)g_usbdev_bus[busid].reg_base;
+    (void)reg_base;
     usb_phy_config_t phy_config = {
         .controller = USB_PHY_CTRL_OTG,
         .otg_mode = USB_OTG_MODE_DEVICE,
@@ -170,6 +171,7 @@ void usb_dc_low_level_init(uint8_t busid)
 void usb_dc_low_level_deinit(uint8_t busid)
 {
     void *reg_base = (void*)g_usbdev_bus[busid].reg_base;
+    (void)reg_base;
     if (s_interrupt_handle[GET_USB_INDEX(reg_base)]) {
         esp_intr_free(s_interrupt_handle[GET_USB_INDEX(reg_base)]);
         s_interrupt_handle[GET_USB_INDEX(reg_base)] = NULL;
@@ -190,6 +192,7 @@ static void usb_hc_interrupt_cb(void *arg_pv)
 void usb_hc_low_level_init(struct usbh_bus *bus)
 {
     void *reg_base = (void*)bus->hcd.reg_base;
+    (void)reg_base;
     // Host Library defaults to internal PHY
     usb_phy_config_t phy_config = {
         .controller = USB_PHY_CTRL_OTG,
@@ -219,6 +222,7 @@ void usb_hc_low_level_init(struct usbh_bus *bus)
 void usb_hc_low_level_deinit(struct usbh_bus *bus)
 {
     void *reg_base = (void*)bus->hcd.reg_base;
+    (void)reg_base;
     if (s_interrupt_handle[GET_USB_INDEX(reg_base)]) {
         esp_intr_free(s_interrupt_handle[GET_USB_INDEX(reg_base)]);
         s_interrupt_handle[GET_USB_INDEX(reg_base)] = NULL;
diff --git a/port/dwc2/usb_hc_dwc2.c b/port/dwc2/usb_hc_dwc2.c
index 838c7b3c..f8de2d11 100644
--- a/port/dwc2/usb_hc_dwc2.c
+++ b/port/dwc2/usb_hc_dwc2.c
@@ -306,9 +306,6 @@ static inline void dwc2_chan_transfer(struct usbh_bus *bus, uint8_t ch_num, uint
 {
     __IO uint32_t tmpreg;
     uint8_t is_oddframe;
-    struct dwc2_chan *chan;
-
-    chan = &g_dwc2_hcd[bus->hcd.hcd_id].chan_pool[ch_num];
 
     /* Initialize the HCTSIZn register */
     USB_OTG_HC(ch_num)->HCTSIZ = (size & USB_OTG_HCTSIZ_XFRSIZ) |
@@ -489,6 +486,10 @@ static void dwc2_chan_free(struct dwc2_chan *chan)
     size_t flags;
 
     flags = usb_osal_enter_critical_section();
+    if (chan->urb) {
+        chan->urb->hcpriv = NULL;
+        chan->urb = NULL;
+    }
     chan->inuse = false;
     usb_osal_leave_critical_section(flags);
 }
@@ -998,11 +999,6 @@ int usbh_submit_urb(struct usbh_urb *urb)
         return -USB_ERR_BUSY;
     }
 
-    chidx = dwc2_chan_alloc(bus);
-    if (chidx == -1) {
-        return -USB_ERR_NOMEM;
-    }
-
     if (urb->ep->bEndpointAddress & 0x80) {
         /* Check if pipe rx fifo is overflow */
         if (USB_GET_MAXPACKETSIZE(urb->ep->wMaxPacketSize) > (g_dwc2_hcd[bus->hcd.hcd_id].user_params.host_rx_fifo_size * 4)) {
@@ -1022,6 +1018,11 @@ int usbh_submit_urb(struct usbh_urb *urb)
         }
     }
 
+    chidx = dwc2_chan_alloc(bus);
+    if (chidx == -1) {
+        return -USB_ERR_NOMEM;
+    }
+
     flags = usb_osal_enter_critical_section();
 
     chan = &g_dwc2_hcd[bus->hcd.hcd_id].chan_pool[chidx];
@@ -1094,8 +1095,6 @@ int usbh_kill_urb(struct usbh_urb *urb)
 
     dwc2_halt(bus, chan->chidx);
 
-    chan->urb = NULL;
-    urb->hcpriv = NULL;
     urb->errorcode = -USB_ERR_SHUTDOWN;
 
     if (urb->timeout) {
@@ -1114,8 +1113,6 @@ static inline void dwc2_urb_waitup(struct usbh_urb *urb)
     struct dwc2_chan *chan;
 
     chan = (struct dwc2_chan *)urb->hcpriv;
-    chan->urb = NULL;
-    urb->hcpriv = NULL;
 
     if (urb->timeout) {
         usb_osal_sem_give(chan->waitsem);
diff --git a/port/ehci/usb_hc_ehci.c b/port/ehci/usb_hc_ehci.c
index e88af6d4..3ad7c9b9 100644
--- a/port/ehci/usb_hc_ehci.c
+++ b/port/ehci/usb_hc_ehci.c
@@ -99,6 +99,10 @@ static void ehci_qh_free(struct usbh_bus *bus, struct ehci_qh_hw *qh)
     size_t flags;
 
     flags = usb_osal_enter_critical_section();
+    if (qh->urb) {
+        qh->urb->hcpriv = NULL;
+        qh->urb = NULL;
+    }
     qtd = EHCI_ADDR2QTD(qh->first_qtd);
 
     while (qtd) {
@@ -616,8 +620,6 @@ static void ehci_urb_waitup(struct usbh_bus *bus, struct usbh_urb *urb)
     struct ehci_qh_hw *qh;
 
     qh = (struct ehci_qh_hw *)urb->hcpriv;
-    qh->urb = NULL;
-    urb->hcpriv = NULL;
 
     qh->remove_in_iaad = 0;
 
@@ -1335,9 +1337,7 @@ int usbh_kill_urb(struct usbh_urb *urb)
     EHCI_HCOR->usbcmd |= (EHCI_USBCMD_PSEN | EHCI_USBCMD_ASEN);
 
     qh = (struct ehci_qh_hw *)urb->hcpriv;
-    urb->hcpriv = NULL;
     urb->errorcode = -USB_ERR_SHUTDOWN;
-    qh->urb = NULL;
 
     if (urb->timeout) {
         usb_osal_sem_give(qh->waitsem);
diff --git a/port/musb/usb_hc_musb.c b/port/musb/usb_hc_musb.c
index 9111177a..b16be99e 100644
--- a/port/musb/usb_hc_musb.c
+++ b/port/musb/usb_hc_musb.c
@@ -477,6 +477,10 @@ static int musb_pipe_alloc(void)
 
 static void musb_pipe_free(struct musb_pipe *pipe)
 {
+    if (pipe->urb) {
+        pipe->urb->hcpriv = NULL;
+        pipe->urb = NULL;
+    }
 #if 0
     pipe->inuse = false;
 #endif
@@ -771,9 +775,7 @@ int usbh_kill_urb(struct usbh_urb *urb)
     flags = usb_osal_enter_critical_section();
 
     pipe = (struct musb_pipe *)urb->hcpriv;
-    urb->hcpriv = NULL;
     urb->errorcode = -USB_ERR_SHUTDOWN;
-    pipe->urb = NULL;
 
     if (urb->ep->bEndpointAddress & 0x80) {
         HWREGH(USB_BASE + MUSB_RXIE_OFFSET) &= ~(1 << (urb->ep->bEndpointAddress & 0x0f));
@@ -800,8 +802,6 @@ static void musb_urb_waitup(struct usbh_urb *urb)
     struct musb_pipe *pipe;
 
     pipe = (struct musb_pipe *)urb->hcpriv;
-    pipe->urb = NULL;
-    urb->hcpriv = NULL;
 
     if (urb->timeout) {
         usb_osal_sem_give(pipe->waitsem);
diff --git a/port/rp2040/usb_hc_rp2040.c b/port/rp2040/usb_hc_rp2040.c
index be8ff976..48f4128f 100644
--- a/port/rp2040/usb_hc_rp2040.c
+++ b/port/rp2040/usb_hc_rp2040.c
@@ -72,6 +72,10 @@ static void rp2040_pipe_free(struct rp2040_pipe *pipe)
     size_t flags;
 
     flags = usb_osal_enter_critical_section();
+    if (pipe->urb) {
+        pipe->urb->hcpriv = NULL;
+        pipe->urb = NULL;
+    }
     pipe->inuse = false;
     usb_osal_leave_critical_section(flags);
 }
@@ -590,9 +594,8 @@ int usbh_kill_urb(struct usbh_urb *urb)
     flags = usb_osal_enter_critical_section();
 
     pipe = (struct rp2040_pipe *)urb->hcpriv;
-    urb->hcpriv = NULL;
     urb->errorcode = -USB_ERR_SHUTDOWN;
-    pipe->urb = NULL;
+
     usb_hw_clear->int_ep_ctrl = 1 << pipe->chidx;
     usb_hw_clear->buf_status = 1 << (pipe->chidx * 2 + 0);
     usb_hw_clear->buf_status = 1 << (pipe->chidx * 2 + 1);
@@ -615,8 +618,6 @@ static void rp2040_urb_waitup(struct usbh_urb *urb)
     struct rp2040_pipe *pipe;
 
     pipe = (struct rp2040_pipe *)urb->hcpriv;
-    pipe->urb = NULL;
-    urb->hcpriv = NULL;
 
     if (urb->timeout) {
         usb_osal_sem_give(pipe->waitsem);