[PATCH] RDMA/rtrs: Avoid Wtautological-constant-out-of-range-compare

[PATCH] RDMA/rtrs: Avoid Wtautological-constant-out-of-range-compare

[Jack Wang]

drivers/infiniband/ulp/rtrs/rtrs-clt.c:1786:19: warning: result of comparison of
constant 'MAX_SESS_QUEUE_DEPTH' (65536) with expression of type 'u16'
(aka 'unsigned short') is always false [-Wtautological-constant-out-of-range-compare]

To fix it, limit MAX_SESS_QUEUE_DEPTH to u16 max, which is 65535, and
drop the check in rtrs-clt, as it's the type u16 max.

Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
---
 drivers/infiniband/ulp/rtrs/rtrs-clt.c | 5 -----
 drivers/infiniband/ulp/rtrs/rtrs-pri.h | 4 ++--
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 8e05a71d8da1..f1fd7ae9ac53 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -1775,11 +1775,6 @@ static int rtrs_rdma_conn_established(struct rtrs_clt_con *con,
 	if (con->c.cid == 0) {
 		queue_depth = le16_to_cpu(msg->queue_depth);
 
-		if (queue_depth > MAX_SESS_QUEUE_DEPTH) {
-			rtrs_err(clt, "Invalid RTRS message: queue=%d\n",
-				  queue_depth);
-			return -ECONNRESET;
-		}
 		if (sess->queue_depth > 0 && queue_depth != sess->queue_depth) {
 			rtrs_err(clt, "Error: queue depth changed\n");
 
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-pri.h b/drivers/infiniband/ulp/rtrs/rtrs-pri.h
index 1705197b8c22..bd06a79fd516 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-pri.h
+++ b/drivers/infiniband/ulp/rtrs/rtrs-pri.h
@@ -53,9 +53,9 @@ enum {
 	 * But mempool_create, create_qp and ib_post_send fail with
 	 * "cannot allocate memory" error if sess_queue_depth is too big.
 	 * Therefore the pratical max value of sess_queue_depth is
-	 * somewhere between 1 and 65536 and it depends on the system.
+	 * somewhere between 1 and 65534 and it depends on the system.
 	 */
-	MAX_SESS_QUEUE_DEPTH = 65536,
+	MAX_SESS_QUEUE_DEPTH = 65535,
 	MIN_CHUNK_SIZE = 8192,
 
 	RTRS_HB_INTERVAL_MS = 5000,
-- 
2.25.1

Re: [PATCH] RDMA/rtrs: Avoid Wtautological-constant-out-of-range-compare

[Jason Gunthorpe]

On Mon, May 31, 2021 at 02:28:35PM +0200, Jack Wang wrote:
> drivers/infiniband/ulp/rtrs/rtrs-clt.c:1786:19: warning: result of comparison of
> constant 'MAX_SESS_QUEUE_DEPTH' (65536) with expression of type 'u16'
> (aka 'unsigned short') is always false [-Wtautological-constant-out-of-range-compare]
> 
> To fix it, limit MAX_SESS_QUEUE_DEPTH to u16 max, which is 65535, and
> drop the check in rtrs-clt, as it's the type u16 max.
> 
> Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
> ---
>  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 5 -----
>  drivers/infiniband/ulp/rtrs/rtrs-pri.h | 4 ++--
>  2 files changed, 2 insertions(+), 7 deletions(-)

I kept the patch as is since the first hunk gets wonky conflicts if it
is squashed

Jason

Re: [PATCH] RDMA/rtrs: Avoid Wtautological-constant-out-of-range-compare

[Jinpu Wang]

On Mon, May 31, 2021 at 8:43 PM Jason Gunthorpe <jgg@ziepe.ca> wrote:
>
> On Mon, May 31, 2021 at 02:28:35PM +0200, Jack Wang wrote:
> > drivers/infiniband/ulp/rtrs/rtrs-clt.c:1786:19: warning: result of comparison of
> > constant 'MAX_SESS_QUEUE_DEPTH' (65536) with expression of type 'u16'
> > (aka 'unsigned short') is always false [-Wtautological-constant-out-of-range-compare]
> >
> > To fix it, limit MAX_SESS_QUEUE_DEPTH to u16 max, which is 65535, and
> > drop the check in rtrs-clt, as it's the type u16 max.
> >
> > Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
> > ---
> >  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 5 -----
> >  drivers/infiniband/ulp/rtrs/rtrs-pri.h | 4 ++--
> >  2 files changed, 2 insertions(+), 7 deletions(-)
>
> I kept the patch as is since the first hunk gets wonky conflicts if it
> is squashed
>
> Jason
Thanks!