Re-enable endpoint after reading GRXSTSP

Disasm · Disasm · commit 0ebd518e6ce0 · 2023-11-25T16:01:25.000+02:00
diff --git a/src/bus.rs b/src/bus.rs
@@ -689,12 +689,17 @@ impl<USB: UsbPeripheral> usb_device::bus::UsbBus for UsbBus<USB> {
                         }
                         0x03 | 0x04 => {
                             // OUT completed | SETUP completed
+
+                            // It's important to read this register before re-enabling the relevant
+                            // endpoint on GD32VF103, otherwise DOEPCTL.EPENA resets back to 0 after
+                            // reading GRXSTSP.
+                            read_reg!(otg_global, regs.global(), GRXSTSP); // pop GRXSTSP
+
                             // Re-enable the endpoint, F429-like chips only
                             if core_id == 0x0000_1200 || core_id == 0x0000_1100 {
                                 let ep = regs.endpoint_out(epnum as usize);
                                 modify_reg!(endpoint_out, ep, DOEPCTL, CNAK: 1, EPENA: 1);
                             }
-                            read_reg!(otg_global, regs.global(), GRXSTSP); // pop GRXSTSP
                         }
                         _ => {
                             read_reg!(otg_global, regs.global(), GRXSTSP); // pop GRXSTSP

Original file line number	Diff line number	Diff line change
`@@ -689,12 +689,17 @@ impl<USB: UsbPeripheral> usb_device::bus::UsbBus for UsbBus<USB> {`
`689`	`689`	`}`
`690`	`690`	`0x03 \| 0x04 => {`
`691`	`691`	`// OUT completed \| SETUP completed`
	`692`	`+`
	`693`	`+ // It's important to read this register before re-enabling the relevant`
	`694`	`+ // endpoint on GD32VF103, otherwise DOEPCTL.EPENA resets back to 0 after`
	`695`	`+ // reading GRXSTSP.`
	`696`	`+ read_reg!(otg_global, regs.global(), GRXSTSP); // pop GRXSTSP`
	`697`	`+`
`692`	`698`	`// Re-enable the endpoint, F429-like chips only`
`693`	`699`	`if core_id == 0x0000_1200 \|\| core_id == 0x0000_1100 {`
`694`	`700`	`let ep = regs.endpoint_out(epnum as usize);`
`695`	`701`	`modify_reg!(endpoint_out, ep, DOEPCTL, CNAK: 1, EPENA: 1);`
`696`	`702`	`}`
`697`		`- read_reg!(otg_global, regs.global(), GRXSTSP); // pop GRXSTSP`
`698`	`703`	`}`
`699`	`704`	`_ => {`
`700`	`705`	`read_reg!(otg_global, regs.global(), GRXSTSP); // pop GRXSTSP`