[PATCH net/stable] can bcm: fix incomplete tx_setup fix
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: 2011-09-29 19:23:16
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 <socketcan@hartkopp.net>
---
@Andre: I checked the changes (which make the code much clearer now) against
your test program and some of mine i modified to test all flags like
STARTTIMER, SETTIMER, TX_ANNOUNCE in different configurations. Please double
check with your setup and send a Tested-by: if it is ok for you.
@Dave: Again sorry for this second patch. The first patch looked sane and
fixed the reported issue - but obviously not the whole problem :-(
bcm.c | 48 +++++++++++++++++++++---------------------------
1 file changed, 21 insertions(+), 27 deletions(-)
diff --git a/net/can/bcm.c b/net/can/bcm.c
index c9cdb8d..c84963d 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; }