4.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
[ Upstream commit 980900d6318066b9f8314bfb87329a20fd0d1ca4 ]
It happens when enable debug log, if set_alt() returns
USB_GADGET_DELAYED_STATUS and usb_composite_setup_continue()
is called before increasing count of @delayed_status,
so fix it by using spinlock of @cdev->lock.
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
Tested-by: Jay Hsu <shih-chieh.hsu@xxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/composite.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1719,6 +1719,8 @@ composite_setup(struct usb_gadget *gadge
*/
if (w_value && !f->get_alt)
break;
+
+ spin_lock(&cdev->lock);
value = f->set_alt(f, w_index, w_value);
if (value == USB_GADGET_DELAYED_STATUS) {
DBG(cdev,
@@ -1728,6 +1730,7 @@ composite_setup(struct usb_gadget *gadge
DBG(cdev, "delayed_status count %d\n",
cdev->delayed_status);
}
+ spin_unlock(&cdev->lock);
break;
case USB_REQ_GET_INTERFACE:
if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
