[PATCH] can: bcm: Account cyclic transmissions only on success

[raoxu]

From: Xu Rao <raoxu@xxxxxxxxxxxxx>

The CAN broadcast manager advances the cyclic frame index and decrements
the initial-interval transmission count even when can_send() fails.
For example, taking the CAN interface down makes can_send() return
-ENETDOWN, but the timer still consumes the configured transmissions and
can report TX_EXPIRED without sending a frame.

Only update cyclic bookkeeping after can_send() succeeds. This matches
the existing successful-send accounting of frames_abs while preserving
the concurrent TX_RESET_MULTI_IDX check.

Signed-off-by: Xu Rao <raoxu@xxxxxxxxxxxxx>
---
 net/can/bcm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 7bd2aa39777a..cd66b23bf95c 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -375,7 +375,7 @@ static void bcm_can_tx(struct bcm_op *op, struct canfd_frame *cf)
 	 * we were sending - a concurrent TX_RESET_MULTI_IDX means this
 	 * frame's bookkeeping belongs to a sequence that no longer exists
 	 */
-	if (!cyclic || op->currframe == idx) {
+	if (!err && (!cyclic || op->currframe == idx)) {
 		op->currframe++;

 		/* reached last frame? */
--
2.50.1