The usb_ep_queue() in printer_write() is possible to call req->complete().
In that case, since tx_complete() calls list_add(&req->list, &dev->tx_reqs),
printer_write() should not call list_add(&req->list, &dev->tx_reqs_active)
because the transfer has already finished. So, this patch checks
the condition of req->list before adding the list in printer_write().
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
This issue can be caused by renesas_usbhs udc driver. I'm not sure
this patch is acceptable or not. So, I marked RFC on this patch.
drivers/usb/gadget/function/f_printer.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index d359efe..01de45e 100644
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -640,10 +640,14 @@ static void tx_complete(struct usb_ep *ep, struct usb_request *req)
spin_unlock_irqrestore(&dev->lock, flags);
mutex_unlock(&dev->lock_printer_io);
return -EAGAIN;
+ } else if (list_empty(&req->list)) {
+ /*
+ * Since usb_ep_queue() is possible to call complete,
+ * we should check the req->list here, and then add
+ * it into dev->tx_reqs_active.
+ */
+ list_add(&req->list, &dev->tx_reqs_active);
}
-
- list_add(&req->list, &dev->tx_reqs_active);
-
}
spin_unlock_irqrestore(&dev->lock, flags);
--
1.9.1
