In case can frames are sent with local loop-back disabled, for instance
doing a "cangen -x", tx_bytes stats are not updated properly in
m_can_echo_tx_event().
More in details, if local loop-back is off, then echo skb is not set
by can_put_echo_skb() at the time m_can_start_xmit() calls it.
So later when tx event interrupt is raised and m_can_echo_tx_event() is
called, can_get_echo_skb() returns 0 and stats->tx_bytes is not
incremented.
In m_can_echo_tx_event(), this patch checks whether message marker
matches a valid skb and if not, data len is retrieved reading tx event
fifo instead of relying on can_get_echo_skb().
This patch has been tested with the ST Accordo5 machine, not yet supported
upstream but which relies on the m_can driver.
Signed-off-by: Jean-Nicolas Graux <jean-nicolas.graux@xxxxxx>
---
drivers/net/can/m_can/m_can.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 9b44940..791a5c6 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -346,6 +346,8 @@ enum m_can_mram_cfg {
/* E1 */
#define TX_EVENT_MM_SHIFT TX_BUF_MM_SHIFT
#define TX_EVENT_MM_MASK (0xff << TX_EVENT_MM_SHIFT)
+#define TX_EVENT_DLC_SHIFT 16
+#define TX_EVENT_DLC_MASK (0xF << TX_EVENT_DLC_SHIFT)
/* address offset and element number for each FIFO/Buffer in the Message RAM */
struct mram_cfg {
@@ -847,7 +849,7 @@ static void m_can_echo_tx_event(struct net_device *dev)
u32 m_can_txefs;
u32 fgi = 0;
int i = 0;
- unsigned int msg_mark;
+ unsigned int msg_mark, txe;
struct m_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
@@ -866,15 +868,21 @@ static void m_can_echo_tx_event(struct net_device *dev)
>> TXEFS_EFGI_SHIFT;
/* get message marker */
- msg_mark = (m_can_txe_fifo_read(priv, fgi, 4) &
- TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT;
+ txe = m_can_txe_fifo_read(priv, fgi, 4);
+ msg_mark = (txe & TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT;
/* ack txe element */
m_can_write(priv, M_CAN_TXEFA, (TXEFA_EFAI_MASK &
(fgi << TXEFA_EFAI_SHIFT)));
/* update stats */
- stats->tx_bytes += can_get_echo_skb(dev, msg_mark);
+ if (priv->can.echo_skb[msg_mark]) {
+ stats->tx_bytes += can_get_echo_skb(dev, msg_mark);
+ } else {
+ u32 dlc = (txe & TX_EVENT_DLC_MASK) >>
+ TX_EVENT_DLC_SHIFT;
+ stats->tx_bytes += can_dlc2len(dlc);
+ }
stats->tx_packets++;
}
}
--
2.7.4
