From 92dc979cf8a5b2439ac2764cd56675407136d329 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Fri, 23 Sep 2011 08:23:47 +0000 Subject: [PATCH] can bcm: fix tx_setup off-by-one errors [ Upstream commit aabdcb0b553b9c9547b1a506b34d55a764745870 ] 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 Signed-off-by: Oliver Hartkopp Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/can/bcm.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/can/bcm.c b/net/can/bcm.c index 184a6572b67e..8838b86f2f27 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -364,9 +364,6 @@ 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); @@ -969,8 +966,9 @@ 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 @@ -978,8 +976,11 @@ 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; } -- 2.39.5