From 520f570c4378d23b595e52213601d62332174462 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 18 Mar 2014 19:27:42 +0100 Subject: [PATCH] can: c_can: Make the code readable If every other line contains line breaks, that's a clear sign for indentation level madness. Split out the inner loop and move the code to a separate function. gcc creates slightly worse code for that, but we'll fix that in the next step. Signed-off-by: Thomas Gleixner [mkl: adjusted subject] Signed-off-by: Marc Kleine-Budde --- drivers/net/can/c_can/c_can.c | 107 ++++++++++++++++++---------------- 1 file changed, 56 insertions(+), 51 deletions(-) diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 1fe79ce50c5a..bd7234eb42f4 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -849,6 +849,52 @@ static u32 c_can_adjust_pending(u32 pend) return pend & ~((1 << lasts) - 1); } +static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv, + u32 pend, int quota) +{ + u32 pkts = 0, ctrl, obj; + + while ((obj = ffs(pend)) && quota > 0) { + pend &= ~BIT(obj - 1); + + c_can_object_get(dev, IF_RX, obj, IF_COMM_ALL & ~IF_COMM_TXRQST); + ctrl = priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, IF_RX)); + + if (ctrl & IF_MCONT_MSGLST) { + int n = c_can_handle_lost_msg_obj(dev, IF_RX, obj, ctrl); + + pkts += n; + quota -= n; + continue; + } + + /* + * This really should not happen, but this covers some + * odd HW behaviour. Do not remove that unless you + * want to brick your machine. + */ + if (!(ctrl & IF_MCONT_NEWDAT)) + continue; + + /* read the data from the message object */ + c_can_read_msg_object(dev, IF_RX, ctrl); + + if (obj < C_CAN_MSG_RX_LOW_LAST) + c_can_mark_rx_msg_obj(dev, IF_RX, ctrl, obj); + else if (obj > C_CAN_MSG_RX_LOW_LAST) + /* activate this msg obj */ + c_can_activate_rx_msg_obj(dev, IF_RX, ctrl, obj); + else if (obj == C_CAN_MSG_RX_LOW_LAST) + /* activate all lower message objects */ + c_can_activate_all_lower_rx_msg_obj(dev, IF_RX, ctrl); + + pkts++; + quota--; + } + + return pkts; +} + /* * theory of operation: * @@ -873,10 +919,8 @@ static u32 c_can_adjust_pending(u32 pend) */ static int c_can_do_rx_poll(struct net_device *dev, int quota) { - u32 num_rx_pkts = 0; - unsigned int msg_obj, msg_ctrl_save; struct c_can_priv *priv = netdev_priv(dev); - u32 val, pend = 0; + u32 pkts = 0, pend = 0, toread, n; /* * It is faster to read only one 16bit register. This is only possible @@ -886,65 +930,26 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota) "Implementation does not support more message objects than 16"); while (quota > 0) { - if (!pend) { pend = priv->read_reg(priv, C_CAN_INTPND1_REG); if (!pend) - return num_rx_pkts; + break; /* * If the pending field has a gap, handle the * bits above the gap first. */ - val = c_can_adjust_pending(pend); + toread = c_can_adjust_pending(pend); } else { - val = pend; + toread = pend; } /* Remove the bits from pend */ - pend &= ~val; - - while ((msg_obj = ffs(val)) && quota > 0) { - val &= ~BIT(msg_obj - 1); - - c_can_object_get(dev, IF_RX, msg_obj, IF_COMM_ALL & - ~IF_COMM_TXRQST); - msg_ctrl_save = priv->read_reg(priv, - C_CAN_IFACE(MSGCTRL_REG, IF_RX)); - - if (msg_ctrl_save & IF_MCONT_MSGLST) { - int n; - - n = c_can_handle_lost_msg_obj(dev, IF_RX, - msg_obj, - msg_ctrl_save); - num_rx_pkts += n; - quota -=n; - continue; - } - - if (!(msg_ctrl_save & IF_MCONT_NEWDAT)) - continue; - - /* read the data from the message object */ - c_can_read_msg_object(dev, IF_RX, msg_ctrl_save); - - if (msg_obj < C_CAN_MSG_RX_LOW_LAST) - c_can_mark_rx_msg_obj(dev, IF_RX, - msg_ctrl_save, msg_obj); - else if (msg_obj > C_CAN_MSG_RX_LOW_LAST) - /* activate this msg obj */ - c_can_activate_rx_msg_obj(dev, IF_RX, - msg_ctrl_save, msg_obj); - else if (msg_obj == C_CAN_MSG_RX_LOW_LAST) - /* activate all lower message objects */ - c_can_activate_all_lower_rx_msg_obj(dev, - IF_RX, msg_ctrl_save); - - num_rx_pkts++; - quota--; - } + pend &= ~toread; + /* Read the objects */ + n = c_can_read_objects(dev, priv, toread, quota); + pkts += n; + quota -= n; } - - return num_rx_pkts; + return pkts; } static inline int c_can_has_and_handle_berr(struct c_can_priv *priv) -- 2.20.1