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 <tglx@linutronix.de>
[mkl: adjusted subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 1fe79ce..bd7234e 100644 (file)
--- 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)