From aabdcb0b553b9c9547b1a506b34d55a764745870 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Fri, 23 Sep 2011 08:23:47 +0000 Subject: can bcm: fix tx_setup off-by-one errors 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 --- net/can/bcm.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'net/can/bcm.c') diff --git a/net/can/bcm.c b/net/can/bcm.c index d6c8ae5b2e6a..c9cdb8d78e70 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -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; } -- cgit v1.2.3 From 12d0d0d3a7349daa95dbfd5d7df8146255bc7c67 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Thu, 29 Sep 2011 15:33:47 -0400 Subject: can bcm: fix incomplete tx_setup fix The commit aabdcb0b553b9c9547b1a506b34d55a764745870 ("can bcm: fix tx_setup off-by-one errors") fixed only a part of the original problem reported by Andre Naujoks. It turned out that the original code needed to be re-ordered to reduce complexity and to finally fix the reported frame counting issues. Signed-off-by: Oliver Hartkopp Signed-off-by: David S. Miller --- net/can/bcm.c | 48 +++++++++++++++++++++--------------------------- 1 file changed, 21 insertions(+), 27 deletions(-) (limited to 'net/can/bcm.c') diff --git a/net/can/bcm.c b/net/can/bcm.c index c9cdb8d78e70..c84963d2dee6 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -344,6 +344,18 @@ static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head, } } +static void bcm_tx_start_timer(struct bcm_op *op) +{ + if (op->kt_ival1.tv64 && op->count) + hrtimer_start(&op->timer, + ktime_add(ktime_get(), op->kt_ival1), + HRTIMER_MODE_ABS); + else if (op->kt_ival2.tv64) + hrtimer_start(&op->timer, + ktime_add(ktime_get(), op->kt_ival2), + HRTIMER_MODE_ABS); +} + static void bcm_tx_timeout_tsklet(unsigned long data) { struct bcm_op *op = (struct bcm_op *)data; @@ -365,23 +377,12 @@ static void bcm_tx_timeout_tsklet(unsigned long data) bcm_send_to_user(op, &msg_head, NULL, 0); } - - /* send (next) frame */ bcm_can_tx(op); - hrtimer_start(&op->timer, - ktime_add(ktime_get(), op->kt_ival1), - HRTIMER_MODE_ABS); - } else { - if (op->kt_ival2.tv64) { + } else if (op->kt_ival2.tv64) + bcm_can_tx(op); - /* send (next) frame */ - bcm_can_tx(op); - hrtimer_start(&op->timer, - ktime_add(ktime_get(), op->kt_ival2), - HRTIMER_MODE_ABS); - } - } + bcm_tx_start_timer(op); } /* @@ -961,28 +962,21 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg, hrtimer_cancel(&op->timer); } - if ((op->flags & STARTTIMER) && - ((op->kt_ival1.tv64 && op->count) || op->kt_ival2.tv64)) { - + if (op->flags & STARTTIMER) { + hrtimer_cancel(&op->timer); /* spec: send can_frame when starting timer */ op->flags |= TX_ANNOUNCE; - - /* 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 - hrtimer_start(&op->timer, op->kt_ival2, - HRTIMER_MODE_REL); } if (op->flags & TX_ANNOUNCE) { bcm_can_tx(op); - if (op->kt_ival1.tv64 && (op->count > 0)) + if (op->count) op->count--; } + if (op->flags & STARTTIMER) + bcm_tx_start_timer(op); + return msg_head->nframes * CFSIZ + MHSIZ; } -- cgit v1.2.3