On Mon, Jun 24, 2019 at 04:15:37PM -0400, Mike Marciniszyn wrote:
> commit da9de5f8527f4b9efc82f967d29a583318c034c7 upstream.
>
> The call to sdma_progress() is called outside the wait lock.
>
> In this case, there is a race condition where sdma_progress() can return
> false and the sdma_engine can idle. If that happens, there will be no
> more sdma interrupts to cause the wakeup and the user_sdma xmit will hang.
>
> Fix by moving the lock to enclose the sdma_progress() call.
>
> Also, delete busycount. The need for this was removed by:
> commit bcad29137a97 ("IB/hfi1: Serve the most starved iowait entry first")
>
> Ported to linux-4.9.y.
Now applied, thanks.
Note, this already is in 4.14.132 and 4.19.57 so I didn't need the
backports for those kernels.
greg k-h
