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can: m_can: m_can_handle_state_errors(): fix CAN state transition to Error Active

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The CAN Error State is determined by the receive and transmit error
counters. The CAN error counters decrease when reception/transmission
is successful, so that a status transition back to the Error Active
status is possible. This transition is not handled by
m_can_handle_state_errors().

Add the missing detection of the Error Active state to
m_can_handle_state_errors() and extend the handling of this state in
m_can_handle_state_change().

Fixes: e0d1f4816f ("can: m_can: add Bosch M_CAN controller support")
Fixes: cd0d83eab2 ("can: m_can: m_can_handle_state_change(): fix state change")
Reviewed-by: Markus Schneider-Pargmann <msp@baylibre.com>
Link: https://patch.msgid.link/20250929-m_can-fix-state-handling-v4-2-682b49b49d9a@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde
2025-08-06 16:56:15 +02:00
parent ba569fb07a
commit 3d9db29b45
1 changed files with 33 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/net/can/m_can/m_can.c
+33 -22
View File
@@ -812,6 +812,9 @@ static int m_can_handle_state_change(struct net_device *dev,
u32 timestamp = 0;
switch (new_state) {
case CAN_STATE_ERROR_ACTIVE:
cdev->can.state = CAN_STATE_ERROR_ACTIVE;
break;
case CAN_STATE_ERROR_WARNING:
/* error warning state */
cdev->can.can_stats.error_warning++;
@@ -841,6 +844,12 @@ static int m_can_handle_state_change(struct net_device *dev,
__m_can_get_berr_counter(dev, &bec);
switch (new_state) {
case CAN_STATE_ERROR_ACTIVE:
cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
cf->data[1] = CAN_ERR_CRTL_ACTIVE;
cf->data[6] = bec.txerr;
cf->data[7] = bec.rxerr;
break;
case CAN_STATE_ERROR_WARNING:
/* error warning state */
cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
@@ -877,30 +886,33 @@ static int m_can_handle_state_change(struct net_device *dev,
return 1;
}
static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
static enum can_state
m_can_state_get_by_psr(struct m_can_classdev *cdev)
{
u32 reg_psr;
reg_psr = m_can_read(cdev, M_CAN_PSR);
if (reg_psr & PSR_BO)
return CAN_STATE_BUS_OFF;
if (reg_psr & PSR_EP)
return CAN_STATE_ERROR_PASSIVE;
if (reg_psr & PSR_EW)
return CAN_STATE_ERROR_WARNING;
return CAN_STATE_ERROR_ACTIVE;
}
static int m_can_handle_state_errors(struct net_device *dev)
{
struct m_can_classdev *cdev = netdev_priv(dev);
int work_done = 0;
enum can_state new_state;
if (psr & PSR_EW && cdev->can.state != CAN_STATE_ERROR_WARNING) {
netdev_dbg(dev, "entered error warning state\n");
work_done += m_can_handle_state_change(dev,
CAN_STATE_ERROR_WARNING);
}
new_state = m_can_state_get_by_psr(cdev);
if (new_state == cdev->can.state)
return 0;
if (psr & PSR_EP && cdev->can.state != CAN_STATE_ERROR_PASSIVE) {
netdev_dbg(dev, "entered error passive state\n");
work_done += m_can_handle_state_change(dev,
CAN_STATE_ERROR_PASSIVE);
}
if (psr & PSR_BO && cdev->can.state != CAN_STATE_BUS_OFF) {
netdev_dbg(dev, "entered error bus off state\n");
work_done += m_can_handle_state_change(dev,
CAN_STATE_BUS_OFF);
}
return work_done;
return m_can_handle_state_change(dev, new_state);
}
static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
@@ -1031,8 +1043,7 @@ static int m_can_rx_handler(struct net_device *dev, int quota, u32 irqstatus)
}
if (irqstatus & IR_ERR_STATE)
work_done += m_can_handle_state_errors(dev,
m_can_read(cdev, M_CAN_PSR));
work_done += m_can_handle_state_errors(dev);
if (irqstatus & IR_ERR_BUS_30X)
work_done += m_can_handle_bus_errors(dev, irqstatus,