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| author | Oliver Hartkopp <oliver@hartkopp.net> | 2009-01-14 21:06:55 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-01-14 21:06:55 -0800 |
| commit | c53a6ee88b0a91bd012ef1b7988c0b93dae6f24d (patch) | |
| tree | 29cd62321b70f58a72b20cbd30bb933b06525df7 /net/can | |
| parent | d57bc36e7aba9e3a00d154f5eff80ff596146fc4 (diff) | |
| download | linux-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.c | 57 |
1 files changed, 30 insertions, 27 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c index 1649c8ab2c2f..b7c7d4651136 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; } /* |