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authorOliver Hartkopp <oliver@hartkopp.net>2009-01-14 21:06:55 -0800
committerDavid S. Miller <davem@davemloft.net>2009-01-14 21:06:55 -0800
commitc53a6ee88b0a91bd012ef1b7988c0b93dae6f24d (patch)
tree29cd62321b70f58a72b20cbd30bb933b06525df7 /net/can
parentd57bc36e7aba9e3a00d154f5eff80ff596146fc4 (diff)
downloadlinux-2.6.38-lt-ux500-c53a6ee88b0a91bd012ef1b7988c0b93dae6f24d.tar.gz
can: fix slowpath issue in hrtimer callback function
Due to the loopback functionality in can_send() we can not invoke it from hardirq context which was done inside the bcm_tx_timeout_handler() hrtimer callback: [ 700.361154] [<c012228c>] warn_slowpath+0x80/0xb6 [ 700.361163] [<c013d559>] valid_state+0x125/0x136 [ 700.361171] [<c013d858>] mark_lock+0x18e/0x332 [ 700.361180] [<c013e300>] __lock_acquire+0x12e/0xb1e [ 700.361189] [<f8ab5915>] bcm_tx_timeout_handler+0x0/0xbc [can_bcm] [ 700.361198] [<c031e20a>] dev_queue_xmit+0x191/0x479 [ 700.361206] [<c01262a7>] __local_bh_disable+0x2b/0x64 [ 700.361213] [<c031e20a>] dev_queue_xmit+0x191/0x479 [ 700.361225] [<f8aa69a1>] can_send+0xd7/0x11a [can] [ 700.361235] [<f8ab522b>] bcm_can_tx+0x9d/0xd9 [can_bcm] [ 700.361245] [<f8ab597f>] bcm_tx_timeout_handler+0x6a/0xbc [can_bcm] [ 700.361255] [<f8ab5915>] bcm_tx_timeout_handler+0x0/0xbc [can_bcm] [ 700.361263] [<c0134143>] __run_hrtimer+0x5a/0x86 [ 700.361273] [<f8ab5915>] bcm_tx_timeout_handler+0x0/0xbc [can_bcm] [ 700.361282] [<c0134a50>] hrtimer_interrupt+0xb9/0x110 This patch moves the rest of the functionality from the hrtimer callback to the already existing tasklet to fix this slowpath problem. Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/bcm.c57
1 files changed, 30 insertions, 27 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 1649c8ab2c2..b7c7d465113 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -347,51 +347,54 @@ static void bcm_tx_timeout_tsklet(unsigned long data)
struct bcm_op *op = (struct bcm_op *)data;
struct bcm_msg_head msg_head;
- /* create notification to user */
- msg_head.opcode = TX_EXPIRED;
- msg_head.flags = op->flags;
- msg_head.count = op->count;
- msg_head.ival1 = op->ival1;
- msg_head.ival2 = op->ival2;
- msg_head.can_id = op->can_id;
- msg_head.nframes = 0;
-
- bcm_send_to_user(op, &msg_head, NULL, 0);
-}
-
-/*
- * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
- */
-static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
-{
- struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
- enum hrtimer_restart ret = HRTIMER_NORESTART;
-
if (op->kt_ival1.tv64 && (op->count > 0)) {
op->count--;
- if (!op->count && (op->flags & TX_COUNTEVT))
- tasklet_schedule(&op->tsklet);
+ if (!op->count && (op->flags & TX_COUNTEVT)) {
+
+ /* create notification to user */
+ msg_head.opcode = TX_EXPIRED;
+ msg_head.flags = op->flags;
+ msg_head.count = op->count;
+ msg_head.ival1 = op->ival1;
+ msg_head.ival2 = op->ival2;
+ msg_head.can_id = op->can_id;
+ msg_head.nframes = 0;
+
+ bcm_send_to_user(op, &msg_head, NULL, 0);
+ }
}
if (op->kt_ival1.tv64 && (op->count > 0)) {
/* send (next) frame */
bcm_can_tx(op);
- hrtimer_forward(hrtimer, ktime_get(), op->kt_ival1);
- ret = HRTIMER_RESTART;
+ hrtimer_start(&op->timer,
+ ktime_add(ktime_get(), op->kt_ival1),
+ HRTIMER_MODE_ABS);
} else {
if (op->kt_ival2.tv64) {
/* send (next) frame */
bcm_can_tx(op);
- hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
- ret = HRTIMER_RESTART;
+ hrtimer_start(&op->timer,
+ ktime_add(ktime_get(), op->kt_ival2),
+ HRTIMER_MODE_ABS);
}
}
+}
- return ret;
+/*
+ * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
+ */
+static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
+{
+ struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
+
+ tasklet_schedule(&op->tsklet);
+
+ return HRTIMER_NORESTART;
}
/*