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>

1 files 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)