From: Jeroen Hofstee <jhofstee@xxxxxxxxxxxxxxxxx> When the CAN interface is closed it the hardwre is put in power down mode, but does not reset the error counters / state. Reset the D_CAN on open, so the reported state and the actual state match. According to [1], the C_CAN module doesn't have the software reset. [1] http://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdf Signed-off-by: Jeroen Hofstee <jhofstee@xxxxxxxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/c_can/c_can.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 9b61bfbea6cd..24c6015f6c92 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -52,6 +52,7 @@ #define CONTROL_EX_PDR BIT(8) /* control register */ +#define CONTROL_SWR BIT(15) #define CONTROL_TEST BIT(7) #define CONTROL_CCE BIT(6) #define CONTROL_DISABLE_AR BIT(5) @@ -572,6 +573,26 @@ static void c_can_configure_msg_objects(struct net_device *dev) IF_MCONT_RCV_EOB); } +static int c_can_software_reset(struct net_device *dev) +{ + struct c_can_priv *priv = netdev_priv(dev); + int retry = 0; + + if (priv->type != BOSCH_D_CAN) + return 0; + + priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_SWR | CONTROL_INIT); + while (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_SWR) { + msleep(20); + if (retry++ > 100) { + netdev_err(dev, "CCTRL: software reset failed\n"); + return -EIO; + } + } + + return 0; +} + /* * Configure C_CAN chip: * - enable/disable auto-retransmission @@ -581,6 +602,11 @@ static void c_can_configure_msg_objects(struct net_device *dev) static int c_can_chip_config(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); + int err; + + err = c_can_software_reset(dev); + if (err) + return err; /* enable automatic retransmission */ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_ENABLE_AR); -- 2.23.0
