[PATCH can-next 09/13] can: gs_usb: gs_usb_state_get_by_hf(): optionally print recived CAN error frames

The previous commit introduced gs_usb_state_get_by_hf() to parse the
current CAN error state from the received CAN error frame.

As there are several gs_usb compatible implementations which slightly
differ in their CAN state and CAN error frame handling add a netdev_dbg()
that prints the received CAN error frame for easier future debugging.

Signed-off-by: Marc Kleine-Budde <[email protected]>
---
 drivers/net/can/usb/gs_usb.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index e41f91b56ab8..2848cb1a75f0 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -670,6 +670,21 @@ gs_usb_state_get_by_hf(const struct gs_can *dev, const struct gs_host_frame *hf,
 			else
 				tx_state = CAN_STATE_ERROR_ACTIVE;
 		}
+
+		const u8 tx_err = hf->classic_can->data[6];
+		const u8 rx_err = hf->classic_can->data[7];
+
+		netdev_dbg(dev->netdev, "host_frame: TX-state='%s/%u' RX-state='%s/%u' %s%s%s%s%s%s%s",
+			   can_get_state_str(tx_state), tx_err,
+			   can_get_state_str(rx_state), rx_err,
+			   hf->can_id & cpu_to_le32(CAN_ERR_BUSOFF) ? "bus-off " : "",
+			   hf->can_id & cpu_to_le32(CAN_ERR_RESTARTED) ?
+			   "restarted-after-bus-off " : "",
+			   err_crtl & CAN_ERR_CRTL_RX_PASSIVE ? "rx-error-passive " : "",
+			   err_crtl & CAN_ERR_CRTL_RX_WARNING ? "rx-error-warning " : "",
+			   err_crtl & CAN_ERR_CRTL_TX_PASSIVE ? "tx-error-passive " : "",
+			   err_crtl & CAN_ERR_CRTL_TX_WARNING ? "tx-error-warning " : "",
+			   err_crtl & CAN_ERR_CRTL_ACTIVE ? "back-to-error-active " : "");
 	} else {
 		tx_state = dev->can.state;
 		rx_state = dev->can.state;

-- 
2.53.0