From 4f7c64cb24853027e28fe0777c3bd0974297389a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=82=E3=83=BC=E3=82=8B=E3=81=A9=E3=82=93?=
 <82225965+rdon-key@users.noreply.github.com>
Date: Fri, 14 Mar 2025 00:39:43 +0900
Subject: [PATCH] =?UTF-8?q?fix(rp2040):=20replace=20loop=20counter=20with?=
 =?UTF-8?q?=20hw=20timer=20for=20USB=20SetAddressReq=E2=80=A6=20(#4796)?=
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* fix(rp2040/rp2350): replace loop counter with hw timer for USB SetAddressRequest timeout.

* fix code format.

---------

Co-authored-by: rdon <you@example.com>
---
 src/machine/machine_rp2040_usb.go | 17 +++++++++--------
 src/machine/machine_rp2350_usb.go | 17 +++++++++--------
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/src/machine/machine_rp2040_usb.go b/src/machine/machine_rp2040_usb.go
index ac7df9820..d69cd6ad5 100644
--- a/src/machine/machine_rp2040_usb.go
+++ b/src/machine/machine_rp2040_usb.go
@@ -169,21 +169,22 @@ func initEndpoint(ep, config uint32) {
 }
 
 func handleUSBSetAddress(setup usb.Setup) bool {
+	// Using 570μs timeout which is exactly the same as SAMD21.
+	const ackTimeout = 570
+
+	rp.USBCTRL_REGS.SIE_STATUS.Set(rp.USBCTRL_REGS_SIE_STATUS_ACK_REC)
 	sendUSBPacket(0, []byte{}, 0)
 
-	// last, set the device address to that requested by host
-	// wait for transfer to complete
-	timeout := 3000
-	rp.USBCTRL_REGS.SIE_STATUS.Set(rp.USBCTRL_REGS_SIE_STATUS_ACK_REC)
+	// Wait for transfer to complete with a timeout.
+	t := timer.timeElapsed()
 	for (rp.USBCTRL_REGS.SIE_STATUS.Get() & rp.USBCTRL_REGS_SIE_STATUS_ACK_REC) == 0 {
-		timeout--
-		if timeout == 0 {
-			return true
+		if dt := timer.timeElapsed() - t; dt >= ackTimeout {
+			return false
 		}
 	}
 
+	// Set the device address to that requested by host.
 	rp.USBCTRL_REGS.ADDR_ENDP.Set(uint32(setup.WValueL) & rp.USBCTRL_REGS_ADDR_ENDP_ADDRESS_Msk)
-
 	return true
 }
 
diff --git a/src/machine/machine_rp2350_usb.go b/src/machine/machine_rp2350_usb.go
index 48fbbcbd0..b42ce09cc 100644
--- a/src/machine/machine_rp2350_usb.go
+++ b/src/machine/machine_rp2350_usb.go
@@ -172,21 +172,22 @@ func initEndpoint(ep, config uint32) {
 }
 
 func handleUSBSetAddress(setup usb.Setup) bool {
+	// Using 570μs timeout which is exactly the same as SAMD21.
+
+	const ackTimeout = 570
+	rp.USB.SIE_STATUS.Set(rp.USB_SIE_STATUS_ACK_REC)
 	sendUSBPacket(0, []byte{}, 0)
 
-	// last, set the device address to that requested by host
-	// wait for transfer to complete
-	timeout := 3000
-	rp.USB.SIE_STATUS.Set(rp.USB_SIE_STATUS_ACK_REC)
+	// Wait for transfer to complete with a timeout.
+	t := timer.timeElapsed()
 	for (rp.USB.SIE_STATUS.Get() & rp.USB_SIE_STATUS_ACK_REC) == 0 {
-		timeout--
-		if timeout == 0 {
-			return true
+		if dt := timer.timeElapsed() - t; dt >= ackTimeout {
+			return false
 		}
 	}
 
+	// Set the device address to that requested by host.
 	rp.USB.ADDR_ENDP.Set(uint32(setup.WValueL) & rp.USB_ADDR_ENDP_ADDRESS_Msk)
-
 	return true
 }