can: m_can: m_can_handle_bus_errors(): add support for handling DLEC error on CAN...

When a frame in CAN FD format has reached the data phase, the next CAN
event (error or valid frame) will be shown in DLEC.

Utilize the dedicated flag (Data Phase Last Error Code: DLEC flag) to
determine the type of last error that occurred in the data phase of a
CAN-FD frame and handle the bus errors.

Signed-off-by: Vivek Yadav <vivek.2311@samsung.com>
Link: https://lore.kernel.org/all/20221018081934.1336690-1-mkl@pengutronix.de
Reviewed-by: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index ebdd3c1..34c76ee 100644 (file)
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -156,6 +156,7 @@ enum m_can_reg {
 #define PSR_EW         BIT(6)
 #define PSR_EP         BIT(5)
 #define PSR_LEC_MASK   GENMASK(2, 0)
+#define PSR_DLEC_MASK  GENMASK(10, 8)
 
 /* Interrupt Register (IR) */
 #define IR_ALL_INT     0xffffffff
@@ -875,9 +876,17 @@ static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
        /* handle lec errors on the bus */
        if (cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
                u8 lec = FIELD_GET(PSR_LEC_MASK, psr);
+               u8 dlec = FIELD_GET(PSR_DLEC_MASK, psr);
 
-               if (is_lec_err(lec))
+               if (is_lec_err(lec)) {
+                       netdev_dbg(dev, "Arbitration phase error detected\n");
                        work_done += m_can_handle_lec_err(dev, lec);
+               }
+               
+               if (is_lec_err(dlec)) {
+                       netdev_dbg(dev, "Data phase error detected\n");
+                       work_done += m_can_handle_lec_err(dev, dlec);
+               }
        }
 
        /* handle protocol errors in arbitration phase */