From dc760b375e50a47847d4942811bd9679beeb5535 Mon Sep 17 00:00:00 2001 From: Jan Altenberg Date: Sun, 27 Mar 2011 18:24:10 -0700 Subject: [PATCH] can: c_can: Fix tx_bytes accounting The current SocketCAN implementation for the Bosch c_can cell doesn't account the TX bytes correctly, because it calls c_can_inval_msg_object() (which clears the msg ctrl register) before reading the DLC value: for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { msg_obj_no = get_tx_echo_msg_obj(priv); c_can_inval_msg_object(dev, 0, msg_obj_no); val = c_can_read_reg32(priv, &priv->regs->txrqst1); if (!(val & (1 << msg_obj_no))) { can_get_echo_skb(dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); stats->tx_bytes += priv->read_reg(priv, &priv->regs->ifregs[0].msg_cntrl) & IF_MCONT_DLC_MASK; stats->tx_packets++; } } So, we will always read 0 for the DLC value and "ifconfig" will report *0* TX Bytes. The fix is quite easy: Just move c_can_inval_msg_object() to the end of the if() statement. So: * We only call c_can_inval_msg_object() if the message was actually transmitted * We read out the DLC value _before_ clearing the msg ctrl register Signed-off-by: Jan Altenberg Acked-by: Kurt Van Dijck Acked-by: Wolfgang Grandegger Signed-off-by: David S. Miller --- drivers/net/can/c_can/c_can.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index d0bffb08aef5..31552959aed7 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -699,7 +699,6 @@ static void c_can_do_tx(struct net_device *dev) for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { msg_obj_no = get_tx_echo_msg_obj(priv); - c_can_inval_msg_object(dev, 0, msg_obj_no); val = c_can_read_reg32(priv, &priv->regs->txrqst1); if (!(val & (1 << msg_obj_no))) { can_get_echo_skb(dev, @@ -708,6 +707,7 @@ static void c_can_do_tx(struct net_device *dev) &priv->regs->ifregs[0].msg_cntrl) & IF_MCONT_DLC_MASK; stats->tx_packets++; + c_can_inval_msg_object(dev, 0, msg_obj_no); } } -- 2.20.1