Simplify handling of partial failures when the command stream is built

diff --git a/klgd.c b/klgd.c
index 2c1a4795c19e20ad47e22a6926ff9657f13b15fc..271bef113bc953b3366919b97e8de422954f4783 100644 (file)
--- a/klgd.c
+++ b/klgd.c
@@ -16,7 +16,6 @@ struct klgd_main_private {
        struct delayed_work work;
        void *device_context;
        unsigned long earliest_update;
-       struct klgd_command_stream *last_stream;
        size_t plugin_count;
        struct klgd_plugin **plugins;
        bool *dontfree;
@@ -124,8 +123,14 @@ int klgd_build_command_stream(struct klgd_main_private *priv, struct klgd_comman
                struct klgd_command_stream *ss;
 
                ret = plugin->get_commands(plugin, &ss, now);
+               /* Something happened while the plugin was building the command stream
+                * but the error is recoverable. Send the incomplete command stream
+                * and try again ASAP. */
+               if (ret == -EAGAIN)
+                       break;
+
                /* Unrecoverable error, ditch the stream and bail out. */
-               if (ret == -EFAULT) {
+               if (ret) {
                        klgd_free_stream(ss);
                        klgd_free_stream(*s);
                        return -EFAULT;
@@ -140,16 +145,9 @@ int klgd_build_command_stream(struct klgd_main_private *priv, struct klgd_comman
                        klgd_free_stream(*s);
                        return -EFAULT;
                }
-
-               /* Something happened while the plugin was building the command stream
-                * but the error is recoverable. Send the incomplete command stream
-                * and try again ASAP. */
-               if (ret == -EAGAIN)
-                       break;
        }
 
        if ((*s)->count) {
-               priv->last_stream = *s;
                printk(KERN_NOTICE "KLGD: Command stream built\n");
                return ret;
        }
@@ -163,7 +161,7 @@ static void klgd_delayed_work(struct work_struct *w)
        struct klgd_main_private *priv = container_of(dw, struct klgd_main_private, work);
        struct klgd_command_stream *s;
        unsigned long now;
-       int ret, ret2;
+       int ret;
 
        priv->try_again = false;
        printk(KERN_NOTICE "KLGD/WQ: --- WQ begins ---\n");
@@ -186,24 +184,23 @@ static void klgd_delayed_work(struct work_struct *w)
        case -ENOENT:
                /* Empty command stream. Plugins have no work for us, exit */
                goto out;
-       case -EFAULT:
+       case 0:
+               break;
+       default:
                /* Unrecoverable error, consider the endpoint dead */
-               printk(KERN_ERR "KLGD: Unrecoverable error while building command stream. No further commands will be sent to the device.\n");
+               printk(KERN_ERR "KLGD: Unrecoverable error while building command stream, ret code %d. No further commands will be sent to the endpoint.\n", ret);
                priv->endpoint_dead = true;
                mutex_unlock(&priv->send_lock);
                return;
-       case 0:
-               break;
-       default:
-               /* TODO: Handle unspecified error */
-               break;
        }
 
-       now = jiffies;  
-       ret2 = priv->send_command_stream(priv->device_context, s);
-       if (ret2) {
-               /* TODO: Error handling */
-               printk(KERN_NOTICE "KLGD/WQ: Unable to send command stream, ret code %d\n", ret);
+       now = jiffies;
+       ret = priv->send_command_stream(priv->device_context, s);
+       if (ret) {
+               printk(KERN_ERR "KLGD/WQ: Unable to send command stream, ret code %d. Marking endpoint dead.\n", ret);
+               priv->endpoint_dead = true;
+               mutex_unlock(&priv->send_lock);
+               return;
        } else
                printk(KERN_NOTICE "KLGD/WQ: Commands sent, time elapsed %u [msec]\n", jiffies_to_msecs(jiffies - now));
        kfree(s);
@@ -211,7 +208,7 @@ static void klgd_delayed_work(struct work_struct *w)
 out:
        mutex_unlock(&priv->send_lock);
 
-       if (ret == -EAGAIN) {
+       if (priv->try_again) {
                queue_delayed_work(priv->wq, &priv->work, TRYAGAIN_DELAY);
                return;
        }
@@ -318,7 +315,6 @@ int klgd_init(struct klgd_main *ctx, void *dev_ctx, int (*callback)(void *, cons
        priv->plugin_count = plugin_count;
 
        priv->device_context = dev_ctx;
-       priv->last_stream = NULL;
        priv->send_command_stream = callback;
 
        ctx->private = priv;
@@ -397,7 +393,7 @@ static void klgd_schedule_update(struct klgd_main_private *priv)
        size_t idx;
 
        /* Recovery update is scheduled. Do not allow any other updates until the recovery is done.
-        * Also do not send updates to dead endpoint */
+        * Also do not send updates to a dead endpoint */
        if (priv->try_again || priv->endpoint_dead)
                return;