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authorOliver Hartkopp <socketcan@hartkopp.net>2011-09-23 08:23:47 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2011-11-11 09:36:25 -0800
commit92dc979cf8a5b2439ac2764cd56675407136d329 (patch)
treebc1171d65440a30eddc8aeef5ffff0bedea3f986 /net/can
parent99dfac8ab234555a54f7fa6e4b7bb08bb355158b (diff)
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 <nautsch@gmail.com> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/bcm.c13
1 files 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;
}