From: Bob Pearson rpearsonhpe@gmail.com
[ Upstream commit bb3ab2979fd69db23328691cb10067861df89037 ]
The code which limited the number of unacknowledged PSNs was incorrect. The PSNs are limited to 24 bits and wrap back to zero from 0x00ffffff. The test was computing a 32 bit value which wraps at 32 bits so that qp->req.psn can appear smaller than the limit when it is actually larger.
Replace '>' test with psn_compare which is used for other PSN comparisons and correctly handles the 24 bit size.
Fixes: 8700e3e7c485 ("Soft RoCE driver") Link: https://lore.kernel.org/r/20201013170741.3590-1-rpearson@hpe.com Signed-off-by: Bob Pearson rpearson@hpe.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/sw/rxe/rxe_req.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c index 5a2d7b0050f4c..463c4b3e73661 100644 --- a/drivers/infiniband/sw/rxe/rxe_req.c +++ b/drivers/infiniband/sw/rxe/rxe_req.c @@ -661,7 +661,8 @@ next_wqe: }
if (unlikely(qp_type(qp) == IB_QPT_RC && - qp->req.psn > (qp->comp.psn + RXE_MAX_UNACKED_PSNS))) { + psn_compare(qp->req.psn, (qp->comp.psn + + RXE_MAX_UNACKED_PSNS)) > 0)) { qp->req.wait_psn = 1; goto exit; }