can bcm: fix tx_setup off-by-one errors (aabdcb0b) · Commits · 戴 / test

This patch fixes two off-by-one errors that canceled each other out. Checking for the same condition two times in bcm_tx_timeout_tsklet() reduced the count of frames to be sent by one. This did not show up the first time tx_setup is invoked as an additional frame is sent due to TX_ANNONCE. Invoking a second tx_setup on the same item led to a reduced (by 1) number of sent frames. Reported-by:

Andre Naujoks <nautsch@gmail.com> Signed-off-by:

Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/can/bcm.c

+7 −6

Original line number	Diff line number	Diff line
		@@ -365,9 +365,6 @@ static void bcm_tx_timeout_tsklet(unsigned long data)

		bcm_send_to_user(op, &msg_head, NULL, 0);
		}
		}

		if (op->kt_ival1.tv64 && (op->count > 0)) {

		/* send (next) frame */
		bcm_can_tx(op);
		@@ -970,8 +967,9 @@ static int bcm_tx_setup(struct bcm_msg_head msg_head, struct msghdr msg,
		/* spec: send can_frame when starting timer */
		op->flags \|= TX_ANNOUNCE;

		if (op->kt_ival1.tv64 && (op->count > 0)) {
		/* op->count-- is done in bcm_tx_timeout_handler */
		/* only start timer when having more frames than sent below */
		if (op->kt_ival1.tv64 && (op->count > 1)) {
		/* op->count-- is done in bcm_tx_timeout_tsklet */
		hrtimer_start(&op->timer, op->kt_ival1,
		HRTIMER_MODE_REL);
		} else
		@@ -979,8 +977,11 @@ static int bcm_tx_setup(struct bcm_msg_head msg_head, struct msghdr msg,
		HRTIMER_MODE_REL);
		}

		if (op->flags & TX_ANNOUNCE)
		if (op->flags & TX_ANNOUNCE) {
		bcm_can_tx(op);
		if (op->kt_ival1.tv64 && (op->count > 0))
		op->count--;
		}

		return msg_head->nframes * CFSIZ + MHSIZ;
		}

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