[PATCH AUTOSEL 4.19 24/34] usb: gadget: fix wrong endpoint desc

[Sasha Levin]

From: EJ Hsu <ejh@xxxxxxxxxx>

[ Upstream commit e5b5da96da50ef30abb39cb9f694e99366404d24 ]

Gadget driver should always use config_ep_by_speed() to initialize
usb_ep struct according to usb device's operating speed. Otherwise,
usb_ep struct may be wrong if usb devcie's operating speed is changed.

The key point in this patch is that we want to make sure the desc pointer
in usb_ep struct will be set to NULL when gadget is disconnected.
This will force it to call config_ep_by_speed() to correctly initialize
usb_ep struct based on the new operating speed when gadget is
re-connected later.

Reviewed-by: Peter Chen <peter.chen@xxxxxxx>
Signed-off-by: EJ Hsu <ejh@xxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/usb/gadget/function/f_ecm.c   | 6 +++++-
 drivers/usb/gadget/function/f_rndis.c | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
index 6ce044008cf6c..460d5d7c984f5 100644
--- a/drivers/usb/gadget/function/f_ecm.c
+++ b/drivers/usb/gadget/function/f_ecm.c
@@ -621,8 +621,12 @@ static void ecm_disable(struct usb_function *f)
 
 	DBG(cdev, "ecm deactivated\n");
 
-	if (ecm->port.in_ep->enabled)
+	if (ecm->port.in_ep->enabled) {
 		gether_disconnect(&ecm->port);
+	} else {
+		ecm->port.in_ep->desc = NULL;
+		ecm->port.out_ep->desc = NULL;
+	}
 
 	usb_ep_disable(ecm->notify);
 	ecm->notify->desc = NULL;
diff --git a/drivers/usb/gadget/function/f_rndis.c b/drivers/usb/gadget/function/f_rndis.c
index d48df36622b74..0d8e4a364ca6e 100644
--- a/drivers/usb/gadget/function/f_rndis.c
+++ b/drivers/usb/gadget/function/f_rndis.c
@@ -618,6 +618,7 @@ static void rndis_disable(struct usb_function *f)
 	gether_disconnect(&rndis->port);
 
 	usb_ep_disable(rndis->notify);
+	rndis->notify->desc = NULL;
 }
 
 /*-------------------------------------------------------------------------*/
-- 
2.20.1