d3ce7940f2
Since commit 6f806b8fa362b53f10947c65af2df8d4acb10b61 "usb: serial: Add flow control between wwan and tty drivers", pushing of received URB data into TTY has been offloaded into a work queue. Only after the data is transferred will the URB be resubmitted. This can race with usb_wwan_resume, which unconditionally submits all the available IN URBs. Hence the double call to usb_anchor_urb will corrupt the anchor list, the second submission will fail, and the following usb_unanchor_urb will result in the list pointing to a now unlinked URB. Thus portdata->in_urb_list will never be exhausted as it can never be traversed fully, and the work function will keep attempting to resubmit the problematic URB over and over again. Fix this by ensuring that an URB to be submitted is both not already anchored and its urb_list member is not part of a list, so that it cannot be submitted multiple times. Also, don't allow the work queue function to resubmit the URB if the interface is suspended. Change-Id: Ib660d01a502be917297ba02db90dd0e53e241707 CRs-Fixed: 390847 Signed-off-by: Jack Pham <jackp@codeaurora.org> Signed-off-by: Neha Pandey <nehap@codeaurora.org>