can: c_can: Avoid status register update for D_CAN

On D_CAN the RXOK, TXOK and LEC bits are cleared/set on read of the
status register. No need to update them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 2aae073a1dc1a226ae87bc7b226e53774a1b0355..b381f7bfb895c3868344c664be916f2b592f71ed 100644 (file)
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -1041,7 +1041,8 @@ static int c_can_handle_bus_err(struct net_device *dev,
        }
 
        /* set a `lec` value so that we can check for updates later */
-       priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
+       if (priv->type != BOSCH_D_CAN)
+               priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
 
        stats->rx_packets++;
        stats->rx_bytes += cf->can_dlc;
@@ -1066,11 +1067,13 @@ static int c_can_poll(struct napi_struct *napi, int quota)
                                        C_CAN_STS_REG);
 
                /* handle Tx/Rx events */
-               if (priv->current_status & STATUS_TXOK)
+               if (priv->current_status & STATUS_TXOK &&
+                   priv->type != BOSCH_D_CAN)
                        priv->write_reg(priv, C_CAN_STS_REG,
                                        priv->current_status & ~STATUS_TXOK);
 
-               if (priv->current_status & STATUS_RXOK)
+               if (priv->current_status & STATUS_RXOK &&
+                   priv->type != BOSCH_D_CAN)
                        priv->write_reg(priv, C_CAN_STS_REG,
                                        priv->current_status & ~STATUS_RXOK);