diff options
| author | Dong Aisheng <b29396@freescale.com> | 2014-10-29 18:45:21 +0800 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2014-11-18 21:35:03 +0100 |
| commit | f6a99649526370c7a88b86736c02f2a74b5b20e7 (patch) | |
| tree | f048cdaebc0c5ac43264ba7b2ae6079e75086a17 /drivers/net/can | |
| parent | 962845da54afe2fc7ebf64c2d8bb5aa65a826b2f (diff) | |
| download | linux-f6a99649526370c7a88b86736c02f2a74b5b20e7.tar.bz2 | |
can: m_can: fix possible sleep in napi poll
The m_can_get_berr_counter function can sleep and it may be called in napi poll
function. Rework it to fix the following warning.
root@imx6qdlsolo:~# cangen can0 -f -L 12 -D 112233445566778899001122
[ 1846.017565] m_can 20e8000.can can0: entered error warning state
[ 1846.023551] ------------[ cut here ]------------
[ 1846.028216] WARNING: CPU: 0 PID: 560 at kernel/locking/mutex.c:867 mutex_trylock+0x218/0x23c()
[ 1846.036889] DEBUG_LOCKS_WARN_ON(in_interrupt())
[ 1846.041263] Modules linked in:
[ 1846.044594] CPU: 0 PID: 560 Comm: cangen Not tainted 3.17.0-rc4-next-20140915-00010-g032d018-dirty #477
[ 1846.054033] Backtrace:
[ 1846.056557] [<80012448>] (dump_backtrace) from [<80012728>] (show_stack+0x18/0x1c)
[ 1846.064180] r6:809a07ec r5:809a07ec r4:00000000 r3:00000000
[ 1846.069966] [<80012710>] (show_stack) from [<806c9ee0>] (dump_stack+0x8c/0xa4)
[ 1846.077264] [<806c9e54>] (dump_stack) from [<8002aa78>] (warn_slowpath_common+0x70/0x94)
[ 1846.085403] r6:806cd1b0 r5:00000009 r4:be1d5c20 r3:be07b0c0
[ 1846.091204] [<8002aa08>] (warn_slowpath_common) from [<8002aad4>] (warn_slowpath_fmt+0x38/0x40)
[ 1846.099951] r8:8119106c r7:80515aa4 r6:be027000 r5:00000001 r4:809d1df4
[ 1846.106830] [<8002aaa0>] (warn_slowpath_fmt) from [<806cd1b0>] (mutex_trylock+0x218/0x23c)
[ 1846.115141] r3:80851c88 r2:8084fb74
[ 1846.118804] [<806ccf98>] (mutex_trylock) from [<80515aa4>] (clk_prepare_lock+0x14/0xf4)
[ 1846.126859] r8:00000040 r7:be1d5cec r6:be027000 r5:be255800 r4:be027000
[ 1846.133737] [<80515a90>] (clk_prepare_lock) from [<80517660>] (clk_prepare+0x14/0x2c)
[ 1846.141583] r5:be255800 r4:be027000
[ 1846.145272] [<8051764c>] (clk_prepare) from [<8041ff14>] (m_can_get_berr_counter+0x20/0xd4)
[ 1846.153672] r4:be255800 r3:be07b0c0
[ 1846.157325] [<8041fef4>] (m_can_get_berr_counter) from [<80420428>] (m_can_poll+0x310/0x8fc)
[ 1846.165809] r7:bd4dc540 r6:00000744 r5:11300000 r4:be255800
[ 1846.171590] [<80420118>] (m_can_poll) from [<8056a468>] (net_rx_action+0xcc/0x1b4)
[ 1846.179204] r10:00000101 r9:be255ebc r8:00000040 r7:be7c3208 r6:8097c100 r5:be7c3200
[ 1846.187192] r4:0000012c
[ 1846.189779] [<8056a39c>] (net_rx_action) from [<8002deec>] (__do_softirq+0xfc/0x2c4)
[ 1846.197568] r10:00000101 r9:8097c088 r8:00000003 r7:8097c080 r6:40000001 r5:8097c08c
[ 1846.205559] r4:00000020
[ 1846.208144] [<8002ddf0>] (__do_softirq) from [<8002e194>] (do_softirq+0x7c/0x88)
[ 1846.215588] r10:00000000 r9:bd516a60 r8:be18ce00 r7:00000000 r6:be255800 r5:8056c0ec
[ 1846.223578] r4:60000093
[ 1846.226163] [<8002e118>] (do_softirq) from [<8002e288>] (__local_bh_enable_ip+0xe8/0x10c)
[ 1846.234386] r4:00000200 r3:be1d4000
[ 1846.238036] [<8002e1a0>] (__local_bh_enable_ip) from [<8056c108>] (__dev_queue_xmit+0x314/0x6b0)
[ 1846.246868] r6:be255800 r5:bd516a00 r4:00000000 r3:be07b0c0
[ 1846.252645] [<8056bdf4>] (__dev_queue_xmit) from [<8056c4b8>] (dev_queue_xmit+0x14/0x18)
Signed-off-by: Dong Aisheng <b29396@freescale.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
| -rw-r--r-- | drivers/net/can/m_can/m_can.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 268ad5064c47..214160b4c314 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -481,11 +481,23 @@ static int m_can_handle_lec_err(struct net_device *dev, return 1; } +static int __m_can_get_berr_counter(const struct net_device *dev, + struct can_berr_counter *bec) +{ + struct m_can_priv *priv = netdev_priv(dev); + unsigned int ecr; + + ecr = m_can_read(priv, M_CAN_ECR); + bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT; + bec->txerr = ecr & ECR_TEC_MASK; + + return 0; +} + static int m_can_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { struct m_can_priv *priv = netdev_priv(dev); - unsigned int ecr; int err; err = clk_prepare_enable(priv->hclk); @@ -498,9 +510,7 @@ static int m_can_get_berr_counter(const struct net_device *dev, return err; } - ecr = m_can_read(priv, M_CAN_ECR); - bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT; - bec->txerr = ecr & ECR_TEC_MASK; + __m_can_get_berr_counter(dev, bec); clk_disable_unprepare(priv->cclk); clk_disable_unprepare(priv->hclk); @@ -544,7 +554,7 @@ static int m_can_handle_state_change(struct net_device *dev, if (unlikely(!skb)) return 0; - m_can_get_berr_counter(dev, &bec); + __m_can_get_berr_counter(dev, &bec); switch (new_state) { case CAN_STATE_ERROR_ACTIVE: |