can: kvaser_usb_leaf: Set Warning state even without bus errors

[ Upstream commit df1b7af2761b935f63b4a53e789d41ed859edf61 ]

kvaser_usb_leaf_rx_error_update_can_state() sets error state according
to error counters when the hardware does not indicate a specific state
directly.

However, this is currently gated behind a check for
M16C_STATE_BUS_ERROR which does not always seem to be set when error
counters are increasing, and may not be set when error counters are
decreasing.

This causes the CAN_STATE_ERROR_WARNING state to not be set in some
cases even when appropriate.

Change the code to set error state from counters even without
M16C_STATE_BUS_ERROR.

The Error-Passive case seems superfluous as it is already set via
M16C_STATE_BUS_PASSIVE flag above, but it is kept for now.

Tested with 0bfd:0124 Kvaser Mini PCI Express 2xHS FW 4.18.778.

Fixes: 080f40a6fa28 ("can: kvaser_usb: Add support for Kvaser CAN/USB devices")
Tested-by: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://lore.kernel.org/all/20221010185237.319219-6-extja@kvaser.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
index 5d96ab8..a6a2608 100644 (file)
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -961,20 +961,16 @@ kvaser_usb_leaf_rx_error_update_can_state(struct kvaser_usb_net_priv *priv,
                new_state = CAN_STATE_BUS_OFF;
        } else if (es->status & M16C_STATE_BUS_PASSIVE) {
                new_state = CAN_STATE_ERROR_PASSIVE;
-       } else if (es->status & M16C_STATE_BUS_ERROR) {
+       } else if ((es->status & M16C_STATE_BUS_ERROR) &&
+                  cur_state >= CAN_STATE_BUS_OFF) {
                /* Guard against spurious error events after a busoff */
-               if (cur_state < CAN_STATE_BUS_OFF) {
-                       if (es->txerr >= 128 || es->rxerr >= 128)
-                               new_state = CAN_STATE_ERROR_PASSIVE;
-                       else if (es->txerr >= 96 || es->rxerr >= 96)
-                               new_state = CAN_STATE_ERROR_WARNING;
-                       else if (cur_state > CAN_STATE_ERROR_ACTIVE)
-                               new_state = CAN_STATE_ERROR_ACTIVE;
-               }
-       }
-
-       if (!es->status)
+       } else if (es->txerr >= 128 || es->rxerr >= 128) {
+               new_state = CAN_STATE_ERROR_PASSIVE;
+       } else if (es->txerr >= 96 || es->rxerr >= 96) {
+               new_state = CAN_STATE_ERROR_WARNING;
+       } else {
                new_state = CAN_STATE_ERROR_ACTIVE;
+       }
 
        if (new_state != cur_state) {
                tx_state = (es->txerr >= es->rxerr) ? new_state : 0;