tree a732474de61de576ad31acc2ac19ef1cf080da8b
parent 32613b2358ea85dee90362ab740b8974d2245995
author Peter Chen <peter.chen@freescale.com> 1333264636 +0800
committer chrmhoffmann <chrmhoffmann@gmail.com> 1586074511 +0200

usb: gadget: fsl_udc_core: dTD's next dtd pointer need to be updated once written

commit 4d0947dec4db1224354e2f6f00ae22ce38e62a43 upstream.

dTD's next dtd pointer need to be updated once CPU writes it, or this
request may not be handled by controller, then host will get NAK from
device forever.

This problem occurs when there is a request is handling, we need to add
a new request to dTD list, if this new request is added before the current
one is finished, the new request is intended to added as next dtd pointer
at current dTD, but without wmb(), the dTD's next dtd pointer may not be
updated when the controller reads it. In that case, the controller will
still get Terminate Bit is 1 at dTD's next dtd pointer, that means there is
no next request, then this new request is missed by controller.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Acked-by: Li Yang <leoli@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>