LP-602 better fix for USB IRQ lockup issue

AIRCAP · AIRCAP · commit 3f2d89fc1174 · 2018-10-15T13:09:18.000+02:00
diff --git a/flight/pios/stm32f4xx/libraries/STM32_USB_OTG_Driver/src/usb_dcd_int.c b/flight/pios/stm32f4xx/libraries/STM32_USB_OTG_Driver/src/usb_dcd_int.c
@@ -681,7 +681,7 @@ static uint32_t DCD_WriteEmptyTxFifo(USB_OTG_CORE_HANDLE *pdev, uint32_t epnum)
   }
   // --- start fix
     uint32_t fifoemptymsk;
-    if (len <= ep->maxpacket)
+    if (len < ep->maxpacket || ep->xfer_count==0)
     {
       // FIFO empty
       fifoemptymsk = 0x1 << epnum;

Original file line number	Diff line number	Diff line change
`@@ -681,7 +681,7 @@ static uint32_t DCD_WriteEmptyTxFifo(USB_OTG_CORE_HANDLE *pdev, uint32_t epnum)`
`681`	`681`	`}`
`682`	`682`	`// --- start fix`
`683`	`683`	`uint32_t fifoemptymsk;`
`684`		`- if (len <= ep->maxpacket)`
	`684`	`+ if (len < ep->maxpacket \|\| ep->xfer_count==0)`
`685`	`685`	`{`
`686`	`686`	`// FIFO empty`
`687`	`687`	`fifoemptymsk = 0x1 << epnum;`