On Mon, May 04, 2020 at 09:09:17AM -0400, Mike Marciniszyn wrote:
> The commit noted below fixed a case where a pq is left on
> the sdma wait list.
>
> It however missed another case.
>
> user_sdma_send_pkts() has two calls from hfi1_user_sdma_process_request().
>
> If the first one fails as indicated by -EBUSY, the pq will be placed on
> the waitlist as by design.
>
> If the second call then succeeds, the pq is still on the waitlist
> setting up a race with the interrupt handler if a subsequent request uses
> a different SDMA engine
>
> Fix by deleting the first call.
>
> The use of pcount and the intent to send a short burst of packets followed
> by the larger balance of packets was never correctly implemented, because
> the two calls always send pcount packets no matter what. A subsequent
> patch will correct that issue.
>
> Fixes: 9a293d1e21a6 ("IB/hfi1: Ensure pq is not left on waitlist")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Reviewed-by: Kaike Wan <kaike.wan@xxxxxxxxx>
> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
> ---
> drivers/infiniband/hw/hfi1/user_sdma.c | 4 ----
> 1 file changed, 4 deletions(-)
Applied to for-rc, thanks
Jason
