4.9-stable review patch. If anyone has any objections, please let me know.
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From: Chunfeng Yun chunfeng.yun@mediatek.com
[ 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@mediatek.com Tested-by: Jay Hsu shih-chieh.hsu@mediatek.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/composite.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -1712,6 +1712,8 @@ 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, @@ -1721,6 +1723,7 @@ 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))