Re: [PATCH] add MPC512x support to mscan

[Wolfgang Grandegger]

Wolfgang Grandegger wrote:
> Wolfram Sang wrote:
>>> Well, to save a test cycle, I'm awaiting for your patch first.
>> That's probably a good idea, I don't even know if this patch applies without
>> the rest of my branch.
>>
>> I just saw there is one FIXME left in the code. If you can comment on this,
>> this would be much appreciated, as I don't know the napi-framework a bit and
>> cannot judge if it should return 0 there or better -ENOSOMETHING in that 
>> case.

I have attached my untested patch for SVN trunk fixing the bus-off
recovery.

> Well, I tried to apply the patch to the SVN trunk, which failed :-).
> Will fix and test now.

Failed again because you fixed the open issue with base_address :-).
Please send your patch and I will check and test.

Wolfgang.

---
 kernel/2.6/drivers/net/can/mscan/mscan.c |   57 +++++++++++++++++++++++--------
 1 file changed, 43 insertions(+), 14 deletions(-)

Index: trunk/kernel/2.6/drivers/net/can/mscan/mscan.c
===================================================================
--- trunk.orig/kernel/2.6/drivers/net/can/mscan/mscan.c
+++ trunk/kernel/2.6/drivers/net/can/mscan/mscan.c
@@ -237,6 +237,16 @@ static int mscan_start(struct net_device
        return 0;
 }
 
+static void mscan_stop(struct net_device *dev)
+{
+       struct mscan_priv *priv = netdev_priv(dev);
+       struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
+
+       out_8(&regs->cantier, 0);
+       out_8(&regs->canrier, 0);
+       mscan_set_mode(dev, MSCAN_INIT_MODE);
+}
+
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,32)
 static int mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 #else
@@ -326,21 +336,20 @@ static netdev_tx_t mscan_start_xmit(stru
        return NETDEV_TX_OK;
 }
 
-static inline int check_set_state(struct net_device *dev, u8 canrflg)
+/* This function returns the old state to see where we came from */
+static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
 {
        struct mscan_priv *priv = netdev_priv(dev);
-       enum can_state state;
-       int ret = 0;
+       enum can_state state, old_state = priv->can.state;
 
-       if (!(canrflg & MSCAN_CSCIF) || priv->can.state > CAN_STATE_BUS_OFF)
-               return 0;
+       if (!(canrflg & MSCAN_CSCIF) || old_state > CAN_STATE_BUS_OFF)
+               return old_state;
 
        state = state_map[max(MSCAN_STATE_RX(canrflg),
                              MSCAN_STATE_TX(canrflg))];
-       if (priv->can.state < state)
-               ret = 1;
+
        priv->can.state = state;
-       return ret;
+       return old_state;
 }
 
 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
@@ -365,6 +374,7 @@ static int mscan_rx_poll(struct net_devi
 #else
        struct net_device_stats *stats = &dev->stats;
 #endif
+       enum can_state old_state;
        int npackets = 0;
        int ret = 1;
        struct sk_buff *skb;
@@ -431,7 +441,16 @@ static int mscan_rx_poll(struct net_devi
                        } else
                                frame->data[1] = 0;
 
-                       if (check_set_state(dev, canrflg)) {
+                       old_state = check_set_state(dev, canrflg);
+                       /* State out of BUS_OFF (automatic recovery) */
+                       if (old_state == CAN_STATE_BUS_OFF
+                           && priv->can.state < old_state) {
+                               frame->can_id |= CAN_ERR_RESTARTED;
+                               priv->can.can_stats.restarts++;
+                               netif_carrier_on(dev);
+                       }
+                       /* State got worse */
+                       if (old_state < priv->can.state) {
                                switch (priv->can.state) {
                                case CAN_STATE_ERROR_WARNING:
                                        frame->can_id |= CAN_ERR_CRTL;
@@ -456,7 +475,20 @@ static int mscan_rx_poll(struct net_devi
                                        break;
                                case CAN_STATE_BUS_OFF:
                                        frame->can_id |= CAN_ERR_BUSOFF;
-                                       can_bus_off(dev);
+                                       /*
+                                        * The MSCAN on the MPC5200 does recover
+                                        * from bus-off automatically. Therefore
+                                        * we stop the chip if the user wants
+                                        * to restart the chip manually.
+                                        */
+                                       if (priv->can.restart_ms) {
+                                               netif_carrier_off(dev);
+                                               dev_dbg(ND2D(dev), "bus-off");
+                                               priv->can.can_stats.bus_off++;
+                                       } else {
+                                               mscan_stop(dev);
+                                               can_bus_off(dev);
+                                       }
                                        break;
                                default:
                                        break;
@@ -661,7 +693,6 @@ static int mscan_open(struct net_device 
 
 static int mscan_close(struct net_device *dev)
 {
-       struct mscan_regs *regs = (struct mscan_regs *)dev->base_addr;
        struct mscan_priv *priv = netdev_priv(dev);
 
        netif_stop_queue(dev);
@@ -669,9 +700,7 @@ static int mscan_close(struct net_device
        napi_disable(&priv->napi);
 #endif
 
-       out_8(&regs->cantier, 0);
-       out_8(&regs->canrier, 0);
-       mscan_set_mode(dev, MSCAN_INIT_MODE);
+       mscan_stop(dev);
        close_candev(dev);
        free_irq(dev->irq, dev);
        priv->open_time = 0;
_______________________________________________
Socketcan-core mailing list
Socketcan-core@lists.berlios.de
https://lists.berlios.de/mailman/listinfo/socketcan-core