isdn/gigaset: fix bas_gigaset interrupt read error handling
authorTilman Schmidt <tilman@imap.cc>
Thu, 30 Sep 2010 13:35:42 +0000 (13:35 +0000)
committerDavid S. Miller <davem@davemloft.net>
Fri, 1 Oct 2010 07:33:36 +0000 (00:33 -0700)
Rework the handling of USB errors in interrupt input reads
to clear halts correctly, delay URB resubmission after errors,
limit retries, and improve error recovery.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/isdn/gigaset/bas-gigaset.c

index 540f6d0bb75422fb7299f23f342e290eaabceff7..71e3fdee441080cfdfc13f9f5a28e0e36c337134 100644 (file)
@@ -109,6 +109,9 @@ struct bas_cardstate {
 
        struct urb              *urb_int_in;    /* URB for interrupt pipe */
        unsigned char           *int_in_buf;
+       struct work_struct      int_in_wq;      /* for usb_clear_halt() */
+       struct timer_list       timer_int_in;   /* int read retry delay */
+       int                     retry_int_in;
 
        spinlock_t              lock;           /* locks all following */
        int                     basstate;       /* bitmap (BS_*) */
@@ -595,6 +598,62 @@ static int atread_submit(struct cardstate *cs, int timeout)
        return 0;
 }
 
+/* int_in_work
+ * workqueue routine to clear halt on interrupt in endpoint
+ */
+
+static void int_in_work(struct work_struct *work)
+{
+       struct bas_cardstate *ucs =
+               container_of(work, struct bas_cardstate, int_in_wq);
+       struct urb *urb = ucs->urb_int_in;
+       struct cardstate *cs = urb->context;
+       int rc;
+
+       /* clear halt condition */
+       rc = usb_clear_halt(ucs->udev, urb->pipe);
+       gig_dbg(DEBUG_USBREQ, "clear_halt: %s", get_usb_rcmsg(rc));
+       if (rc == 0)
+               /* success, resubmit interrupt read URB */
+               rc = usb_submit_urb(urb, GFP_ATOMIC);
+       if (rc != 0 && rc != -ENODEV) {
+               dev_err(cs->dev, "clear halt failed: %s\n", get_usb_rcmsg(rc));
+               rc = usb_lock_device_for_reset(ucs->udev, ucs->interface);
+               if (rc == 0) {
+                       rc = usb_reset_device(ucs->udev);
+                       usb_unlock_device(ucs->udev);
+               }
+       }
+       ucs->retry_int_in = 0;
+}
+
+/* int_in_resubmit
+ * timer routine for interrupt read delayed resubmit
+ * argument:
+ *     controller state structure
+ */
+static void int_in_resubmit(unsigned long data)
+{
+       struct cardstate *cs = (struct cardstate *) data;
+       struct bas_cardstate *ucs = cs->hw.bas;
+       int rc;
+
+       if (ucs->retry_int_in++ >= BAS_RETRY) {
+               dev_err(cs->dev, "interrupt read: giving up after %d tries\n",
+                       ucs->retry_int_in);
+               usb_queue_reset_device(ucs->interface);
+               return;
+       }
+
+       gig_dbg(DEBUG_USBREQ, "%s: retry %d", __func__, ucs->retry_int_in);
+       rc = usb_submit_urb(ucs->urb_int_in, GFP_ATOMIC);
+       if (rc != 0 && rc != -ENODEV) {
+               dev_err(cs->dev, "could not resubmit interrupt URB: %s\n",
+                       get_usb_rcmsg(rc));
+               usb_queue_reset_device(ucs->interface);
+       }
+}
+
 /* read_int_callback
  * USB completion handler for interrupt pipe input
  * called by the USB subsystem in interrupt context
@@ -615,19 +674,29 @@ static void read_int_callback(struct urb *urb)
 
        switch (status) {
        case 0:                 /* success */
+               ucs->retry_int_in = 0;
                break;
+       case -EPIPE:                    /* endpoint stalled */
+               schedule_work(&ucs->int_in_wq);
+               /* fall through */
        case -ENOENT:                   /* cancelled */
        case -ECONNRESET:               /* cancelled (async) */
        case -EINPROGRESS:              /* pending */
-               /* ignore silently */
+       case -ENODEV:                   /* device removed */
+       case -ESHUTDOWN:                /* device shut down */
+               /* no further action necessary */
                gig_dbg(DEBUG_USBREQ, "%s: %s",
                        __func__, get_usb_statmsg(status));
                return;
-       case -ENODEV:                   /* device removed */
-       case -ESHUTDOWN:                /* device shut down */
-               gig_dbg(DEBUG_USBREQ, "%s: device disconnected", __func__);
+       case -EPROTO:                   /* protocol error or unplug */
+       case -EILSEQ:
+       case -ETIME:
+               /* resubmit after delay */
+               gig_dbg(DEBUG_USBREQ, "%s: %s",
+                       __func__, get_usb_statmsg(status));
+               mod_timer(&ucs->timer_int_in, jiffies + HZ / 10);
                return;
-       default:                /* severe trouble */
+       default:                /* other errors: just resubmit */
                dev_warn(cs->dev, "interrupt read: %s\n",
                         get_usb_statmsg(status));
                goto resubmit;
@@ -705,6 +774,13 @@ static void read_int_callback(struct urb *urb)
                        break;
                }
                spin_lock_irqsave(&cs->lock, flags);
+               if (ucs->basstate & BS_ATRDPEND) {
+                       spin_unlock_irqrestore(&cs->lock, flags);
+                       dev_warn(cs->dev,
+       "HD_RECEIVEATDATA_ACK(%d) during HD_READ_ATMESSAGE(%d) ignored\n",
+                                l, ucs->rcvbuf_size);
+                       break;
+               }
                if (ucs->rcvbuf_size) {
                        /* throw away previous buffer - we have no queue */
                        dev_err(cs->dev,
@@ -717,7 +793,6 @@ static void read_int_callback(struct urb *urb)
                if (ucs->rcvbuf == NULL) {
                        spin_unlock_irqrestore(&cs->lock, flags);
                        dev_err(cs->dev, "out of memory receiving AT data\n");
-                       error_reset(cs);
                        break;
                }
                ucs->rcvbuf_size = l;
@@ -727,13 +802,10 @@ static void read_int_callback(struct urb *urb)
                        kfree(ucs->rcvbuf);
                        ucs->rcvbuf = NULL;
                        ucs->rcvbuf_size = 0;
-                       if (rc != -ENODEV) {
-                               spin_unlock_irqrestore(&cs->lock, flags);
-                               error_reset(cs);
-                               break;
-                       }
                }
                spin_unlock_irqrestore(&cs->lock, flags);
+               if (rc < 0 && rc != -ENODEV)
+                       error_reset(cs);
                break;
 
        case HD_RESET_INTERRUPT_PIPE_ACK:
@@ -2138,7 +2210,9 @@ static int gigaset_initcshw(struct cardstate *cs)
        setup_timer(&ucs->timer_ctrl, req_timeout, (unsigned long) cs);
        setup_timer(&ucs->timer_atrdy, atrdy_timeout, (unsigned long) cs);
        setup_timer(&ucs->timer_cmd_in, cmd_in_timeout, (unsigned long) cs);
+       setup_timer(&ucs->timer_int_in, int_in_resubmit, (unsigned long) cs);
        init_waitqueue_head(&ucs->waitqueue);
+       INIT_WORK(&ucs->int_in_wq, int_in_work);
 
        return 1;
 }
@@ -2286,6 +2360,7 @@ static int gigaset_probe(struct usb_interface *interface,
                        get_usb_rcmsg(rc));
                goto error;
        }
+       ucs->retry_int_in = 0;
 
        /* tell the device that the driver is ready */
        rc = req_submit(cs->bcs, HD_DEVICE_INIT_ACK, 0, 0);
@@ -2338,10 +2413,12 @@ static void gigaset_disconnect(struct usb_interface *interface)
        /* stop driver (common part) */
        gigaset_stop(cs);
 
-       /* stop timers and URBs, free ressources */
+       /* stop delayed work and URBs, free ressources */
        del_timer_sync(&ucs->timer_ctrl);
        del_timer_sync(&ucs->timer_atrdy);
        del_timer_sync(&ucs->timer_cmd_in);
+       del_timer_sync(&ucs->timer_int_in);
+       cancel_work_sync(&ucs->int_in_wq);
        freeurbs(cs);
        usb_set_intfdata(interface, NULL);
        kfree(ucs->rcvbuf);
@@ -2404,12 +2481,14 @@ static int gigaset_suspend(struct usb_interface *intf, pm_message_t message)
                /* in case of timeout, proceed anyway */
        }
 
-       /* kill all URBs and timers that might still be pending */
+       /* kill all URBs and delayed work that might still be pending */
        usb_kill_urb(ucs->urb_ctrl);
        usb_kill_urb(ucs->urb_int_in);
        del_timer_sync(&ucs->timer_ctrl);
        del_timer_sync(&ucs->timer_atrdy);
        del_timer_sync(&ucs->timer_cmd_in);
+       del_timer_sync(&ucs->timer_int_in);
+       cancel_work_sync(&ucs->int_in_wq);
 
        gig_dbg(DEBUG_SUSPEND, "suspend complete");
        return 0;
@@ -2431,6 +2510,7 @@ static int gigaset_resume(struct usb_interface *intf)
                        get_usb_rcmsg(rc));
                return rc;
        }
+       ucs->retry_int_in = 0;
 
        /* clear suspend flag to reallow activity */
        update_basstate(ucs, 0, BS_SUSPEND);