[PATCH 4.14 126/222] usb: gadget: udc: renesas_usb3: Fix b-device mode for "workaround"

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>

commit afc92514a34c7414b28047b1205a6b709103c699 upstream.

If the "workaround_for_vbus" is true, the driver will not call
usb_disconnect(). So, since the controller keeps some registers'
value, the driver doesn't re-enumarate suitable speed after
the b-device mode is disabled. To fix the issue, this patch
adds usb_disconnect() calling in renesas_usb3_b_device_write()
if workaround_for_vbus is true.

Fixes: 43ba968b00ea ("usb: gadget: udc: renesas_usb3: add debugfs to set the b-device mode")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.14+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/gadget/udc/renesas_usb3.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -2374,6 +2374,9 @@ static ssize_t renesas_usb3_b_device_wri
 	else
 		usb3->forced_b_device = false;
 
+	if (usb3->workaround_for_vbus)
+		usb3_disconnect(usb3);
+
 	/* Let this driver call usb3_connect() anyway */
 	usb3_check_id(usb3);