When OS reboot, device is still in normal mode. Probing
will fail with this error message:
refusing to configure device when in normal mode
(unnamed net_device) (uninitialized): failed to enable configuration mode
Failed registering m_can device -EBUSY
The log can be traced, it's from:
m_can_dev_setup
-> m_can_niso_supported
-> m_can_config_enable
-> m_can_cccr_update_bits
In commit cd5a46ce6fa6 ("can: m_can: don't enable transceiver when
probing"), m_can_niso_supported() was reworked to call
m_can_config_enable(). However, in m_can_config_enable(), it's noted
that CCCR_INIT must be set in order to set CCCR_CCE. The CCCR_INIT
bit is set later in m_can_dev_setup().
To fix the problem, move forcing standby mode (set CCCR_INIT) lines
before m_can_niso_supported() line in m_can_dev_setup().
Fixes: cd5a46ce6fa6 ("can: m_can: don't enable transceiver when probing")
Signed-off-by: Renjaya Raga Zenta <ragazenta@xxxxxxxxx>
---
Link: https://lore.kernel.org/linux-can/20241106123700.119074-1-renjaya.zenta@xxxxxxxxxxxxxxx
---
drivers/net/can/m_can/m_can.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 533bcb77c9f934e5840b076ded948f8256ad2ad0..9345b181c5e31e1507a4dadc31e5f15545e1dc98 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1685,7 +1685,7 @@ static int m_can_niso_supported(struct m_can_classdev *cdev)
static int m_can_dev_setup(struct m_can_classdev *cdev)
{
struct net_device *dev = cdev->net;
- int m_can_version, err, niso;
+ int m_can_version, err, ret, niso;
m_can_version = m_can_check_core_release(cdev);
/* return if unsupported version */
@@ -1710,6 +1710,12 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
CAN_CTRLMODE_FD |
CAN_CTRLMODE_ONE_SHOT;
+ /* Forcing standby mode should be redundant, as the chip should be in
+ * standby after a reset. Write the INIT bit anyways, should the chip
+ * be configured by previous stage.
+ */
+ ret = m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT);
+
/* Set properties depending on M_CAN version */
switch (cdev->version) {
case 30:
@@ -1746,11 +1752,7 @@ static int m_can_dev_setup(struct m_can_classdev *cdev)
return -EINVAL;
}
- /* Forcing standby mode should be redundant, as the chip should be in
- * standby after a reset. Write the INIT bit anyways, should the chip
- * be configured by previous stage.
- */
- return m_can_cccr_update_bits(cdev, CCCR_INIT, CCCR_INIT);
+ return ret;
}
static void m_can_stop(struct net_device *dev)
---
base-commit: c7d876495ffad298d7f5fa252000c80fd4fd1b74
change-id: 20241217-m_can_fix-af60055d7c96
Best regards,
--
Renjaya Raga Zenta <ragazenta@xxxxxxxxx>
