[ Upstream commit 2c09b50efcad985cf920ca88baa9aa52b1999dcc ]
After calling m_can_stop() an interrupt may be pending or NAPI might
still be executed. This means the driver might still touch registers
of the IP core after the clocks have been disabled. This is not good
practice and might lead to aborts depending on the SoC integration.
To avoid these potential problems, make m_can_close() symmetric to
m_can_open(), i.e. stop the clocks at the end, right before shutting
down the transceiver.
Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support")
Link: https://patch.msgid.link/20240910-can-m_can-fix-ifup-v3-2-6c1720ba45ce@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d836cb5fe045463cdab15ad6f278f7c7c194228f ]
Add support for implementing transceiver node as phy. The max_bitrate
is obtained by getting a phy attribute.
Link: https://lore.kernel.org/r/20210724174001.553047-1-mkl@pengutronix.de
Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Stable-dep-of: 2c09b50efcad ("can: m_can: m_can_close(): stop clocks after device has been shut down")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7dd9c26bd6cf679bcfdef01a8659791aa6487a29 upstream.
The mcp251x_hw_wake() function is called with the mpc_lock mutex held and
disables the interrupt handler so that no interrupts can be processed while
waking the device. If an interrupt has already occurred then waiting for
the interrupt handler to complete will deadlock because it will be trying
to acquire the same mutex.
CPU0 CPU1
---- ----
mcp251x_open()
mutex_lock(&priv->mcp_lock)
request_threaded_irq()
<interrupt>
mcp251x_can_ist()
mutex_lock(&priv->mcp_lock)
mcp251x_hw_wake()
disable_irq() <-- deadlock
Use disable_irq_nosync() instead because the interrupt handler does
everything while holding the mutex so it doesn't matter if it's still
running.
Fixes: 8ce8c0abcba3 ("can: mcp251x: only reset hardware as required")
Signed-off-by: Simon Arlott <simon@octiron.net>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/4fc08687-1d80-43fe-9f0d-8ef8475e75f6@0882a8b5-c6c3-11e9-b005-00805fc181fe.uuid.home.arpa
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0d34d8163fd87978a6abd792e2d8ad849f4c3d57 ]
As the potential failure of usb_submit_urb(), it should be better to
return the err variable to catch the error.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Link: https://lore.kernel.org/all/20240521041020.1519416-1-nichen@iscas.ac.cn
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 19d5b2698c35b2132a355c67b4d429053804f8cc upstream.
Explicitly set the 'family' driver_info struct member for leafimx.
Previously, the correct operation relied on KVASER_LEAF being the first
defined value in enum kvaser_usb_leaf_family.
Fixes: e6c80e601053 ("can: kvaser_usb: kvaser_usb_leaf: fix CAN clock frequency regression")
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://lore.kernel.org/all/20240628194529.312968-1-extja@kvaser.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6841cab8c4504835e4011689cbdb3351dec693fd ]
This race condition was discovered while updating the at91_can driver
to use can_bus_off(). The following scenario describes how the
converted at91_can driver would behave.
When a CAN device goes into BUS-OFF state, the driver usually
stops/resets the CAN device and calls can_bus_off().
This function sets the netif carrier to off, and (if configured by
user space) schedules a delayed work that calls can_restart() to
restart the CAN device.
The can_restart() function first checks if the carrier is off and
triggers an error message if the carrier is OK.
Then it calls the driver's do_set_mode() function to restart the
device, then it sets the netif carrier to on. There is a race window
between these two calls.
The at91 CAN controller (observed on the sama5d3, a single core 32 bit
ARM CPU) has a hardware limitation. If the device goes into bus-off
while sending a CAN frame, there is no way to abort the sending of
this frame. After the controller is enabled again, another attempt is
made to send it.
If the bus is still faulty, the device immediately goes back to the
bus-off state. The driver calls can_bus_off(), the netif carrier is
switched off and another can_restart is scheduled. This occurs within
the race window before the original can_restart() handler marks the
netif carrier as OK. This would cause the 2nd can_restart() to be
called with an OK netif carrier, resulting in an error message.
The flow of the 1st can_restart() looks like this:
can_restart()
// bail out if netif_carrier is OK
netif_carrier_ok(dev)
priv->do_set_mode(dev, CAN_MODE_START)
// enable CAN controller
// sama5d3 restarts sending old message
// CAN devices goes into BUS_OFF, triggers IRQ
// IRQ handler start
at91_irq()
at91_irq_err_line()
can_bus_off()
netif_carrier_off()
schedule_delayed_work()
// IRQ handler end
netif_carrier_on()
The 2nd can_restart() will be called with an OK netif carrier and the
error message will be printed.
To close the race window, first set the netif carrier to on, then
restart the controller. In case the restart fails with an error code,
roll back the netif carrier to off.
Fixes: 39549eef3587 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-2-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fe5c9940dfd8ba0c73672dddb30acd1b7a11d4c7 ]
During testing, I triggered a can_restart() with the netif carrier
being OK [1]. The BUG_ON, which checks if the carrier is OK, results
in a fatal kernel crash. This is neither helpful for debugging nor for
a production system.
[1] The root cause is a race condition in can_restart() which will be
fixed in the next patch.
Do not crash the kernel, issue an error message instead, and continue
restarting the CAN device anyway.
Fixes: 39549eef3587 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-1-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
