U-Boot has an older version of the Linux gadget API, where USB endpoints
returned by usb_ep_autoconfig() are not automatically claimed. As written
in the documentation comment:
"To prevent the endpoint from being returned by a later autoconfig call,
claim it by assigning ep->driver_data to some non-null value."
Right now f_acm doesn't do that, which means that e.g. ep_in and ep_notify
may end up being assigned the same endpoint. Surprisingly, the ACM console
is still somehow working, but this is not the expected behavior. It will
break with a later commit that disallows calling usb_ep_enable() multiple
times.
Fix this by assigning some data to ep->driver_data, similar to the other
gadget drivers.
Fixes: fc2b399ac03b ("usb: gadget: Add CDC ACM function")
Signed-off-by: Stephan Gerhold <stephan.gerh...@linaro.org>
---
drivers/usb/gadget/f_acm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/gadget/f_acm.c b/drivers/usb/gadget/f_acm.c
index
f18c6a0a76110df62e925de1882316eed463b343..2665fa4168f99b35a8c595aa24cb3fc4e8ab8529
100644
--- a/drivers/usb/gadget/f_acm.c
+++ b/drivers/usb/gadget/f_acm.c
@@ -238,18 +238,21 @@ static int acm_bind(struct usb_configuration *c, struct
usb_function *f)
return -ENODEV;
f_acm->ep_in = ep;
+ ep->driver_data = c->cdev; /* claim */
ep = usb_ep_autoconfig(gadget, &acm_fs_out_desc);
if (!ep)
return -ENODEV;
f_acm->ep_out = ep;
+ ep->driver_data = c->cdev; /* claim */
ep = usb_ep_autoconfig(gadget, &acm_fs_notify_desc);
if (!ep)
return -ENODEV;
f_acm->ep_notify = ep;
+ ep->driver_data = c->cdev; /* claim */
if (gadget_is_dualspeed(gadget)) {
/* Assume endpoint addresses are the same for both speeds */
--
2.47.2
