Re: [PATCH] can: c_can: fix segfault during rmmod
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2012-09-27 11:12:06
On 09/27/2012 12:41 PM, AnilKumar Ch wrote:
This patch fixes an oops which occurs during unloading the driver. The problem is that clock is not enabled during unregister_c_can_dev() which does c_can/d_can module interrupts enable/disable.
Looking at the code, I see that
c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
is called during c_can_stop().
This should be sufficient as during unregister_netdev() the driver's
close function will be called (it the netdev is still opened) [1].
I think your patch
4cdd34b can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controller
has not reached the David's net branch, so I prefer to remove the
offending:
c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
call from the unregister_c_can_dev().
Marc
[1] I recently fixed a OOPS in another driver with this stack trace:
[ 172.954498] [<bf00c768>] (ti_hecc_close+0xb0/0x100 [ti_hecc]) from [<c033be58>] (__dev__registered_many+0xc0/0x2a0)
[ 172.984161] [<c033c098>] (rollback_registered_many+0xc0/0x2a0) from [<c033c2f8>] (rollback_registered+0x20/0x30)
[ 172.994750] [<c033c2f8>] (rollback_registered+0x20/0x30) from [<c033c370>] (unregister_netdevice_queue+0x68/0x98)
[ 173.005401] [<c033c370>] (unregister_netdevice_queue+0x68/0x98) from [<c033c3b8>] (unregister_netdev+0x18/0x20)
[ 173.015899] [<c033c3b8>] (unregister_netdev+0x18/0x20) from [<bf00d3ac>] (ti_hecc_remove+0x60/0x80 [ti_hecc])
[ 173.026245] [<bf00d3ac>] (ti_hecc_remove+0x60/0x80 [ti_hecc]) from [<c02842dc>] (platform_drv_remove+0x14/0x18)
[ 173.036712] [<c02842dc>] (platform_drv_remove+0x14/0x18) from [<c0282f90>] (__device_release_driver+0x7c/0xbc)
Marc
quoted hunk ↗ jump to hunk
Signed-off-by: AnilKumar Ch <redacted> --- drivers/net/can/c_can/c_can.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 2c4a21f..638e3cc 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c@@ -1265,8 +1265,10 @@ void unregister_c_can_dev(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); + c_can_pm_runtime_get_sync(priv); /* disable all interrupts */ c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS); + c_can_pm_runtime_put_sync(priv); unregister_candev(dev);
-- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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