[PATCH 4.14 11/74] usb: gadget: fix wrong endpoint desc

From: Greg Kroah-Hartman
Date: Tue Jan 07 2020 - 16:14:53 EST


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 4c488d15b6f6..dc99ed94f03d 100644
--- a/drivers/usb/gadget/function/f_ecm.c
+++ b/drivers/usb/gadget/function/f_ecm.c
@@ -625,8 +625,12 @@ 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 c7c5b3ce1d98..2bde68f5d246 100644
--- a/drivers/usb/gadget/function/f_rndis.c
+++ b/drivers/usb/gadget/function/f_rndis.c
@@ -622,6 +622,7 @@ static void rndis_disable(struct usb_function *f)
gether_disconnect(&rndis->port);

usb_ep_disable(rndis->notify);
+ rndis->notify->desc = NULL;
}

/*-------------------------------------------------------------------------*/
--
2.20.1