releases/2.6.32.12/usb-cdc-acm-update-to-new-autopm-api.patch

   1 From 97d35f95552c9a0ee4777a7f04431a9fd1260478 Mon Sep 17 00:00:00 2001
   2 From: Oliver Neukum <oliver@neukum.org>
   3 Date: Wed, 16 Dec 2009 17:05:57 +0100
   4 Subject: USB: cdc-acm: Update to new autopm API
   5
   6 From: Oliver Neukum <oliver@neukum.org>
   7
   8 commit 97d35f95552c9a0ee4777a7f04431a9fd1260478 upstream.
   9
  10 Update cdc-acm to the async methods eliminating the workqueue
  11
  12 [This fixes a reported lockup for the cdc-acm driver - gregkh]
  13
  14 Signed-off-by: Oliver Neukum <oliver@neukum.org>
  15 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  16
  17 ---
  18  drivers/usb/class/cdc-acm.c |   43 ++++++++++++++++++++++---------------------
  19  drivers/usb/class/cdc-acm.h |    1 -
  20  2 files changed, 22 insertions(+), 22 deletions(-)
  21
  22 --- a/drivers/usb/class/cdc-acm.c
  23 +++ b/drivers/usb/class/cdc-acm.c
  24 @@ -170,6 +170,7 @@ static void acm_write_done(struct acm *a
  25  {
  26         wb->use = 0;
  27         acm->transmitting--;
  28 +       usb_autopm_put_interface_async(acm->control);
  29  }
  30
  31  /*
  32 @@ -211,9 +212,12 @@ static int acm_write_start(struct acm *a
  33         }
  34
  35         dbg("%s susp_count: %d", __func__, acm->susp_count);
  36 +       usb_autopm_get_interface_async(acm->control);
  37         if (acm->susp_count) {
  38 -               acm->delayed_wb = wb;
  39 -               schedule_work(&acm->waker);
  40 +               if (!acm->delayed_wb)
  41 +                       acm->delayed_wb = wb;
  42 +               else
  43 +                       usb_autopm_put_interface_async(acm->control);
  44                 spin_unlock_irqrestore(&acm->write_lock, flags);
  45                 return 0;       /* A white lie */
  46         }
  47 @@ -534,23 +538,6 @@ static void acm_softint(struct work_stru
  48         tty_kref_put(tty);
  49  }
  50
  51 -static void acm_waker(struct work_struct *waker)
  52 -{
  53 -       struct acm *acm = container_of(waker, struct acm, waker);
  54 -       int rv;
  55 -
  56 -       rv = usb_autopm_get_interface(acm->control);
  57 -       if (rv < 0) {
  58 -               dev_err(&acm->dev->dev, "Autopm failure in %s\n", __func__);
  59 -               return;
  60 -       }
  61 -       if (acm->delayed_wb) {
  62 -               acm_start_wb(acm, acm->delayed_wb);
  63 -               acm->delayed_wb = NULL;
  64 -       }
  65 -       usb_autopm_put_interface(acm->control);
  66 -}
  67 -
  68  /*
  69   * TTY handlers
  70   */
  71 @@ -1178,7 +1165,6 @@ made_compressed_probe:
  72         acm->urb_task.func = acm_rx_tasklet;
  73         acm->urb_task.data = (unsigned long) acm;
  74         INIT_WORK(&acm->work, acm_softint);
  75 -       INIT_WORK(&acm->waker, acm_waker);
  76         init_waitqueue_head(&acm->drain_wait);
  77         spin_lock_init(&acm->throttle_lock);
  78         spin_lock_init(&acm->write_lock);
  79 @@ -1343,7 +1329,6 @@ static void stop_data_traffic(struct acm
  80         tasklet_enable(&acm->urb_task);
  81
  82         cancel_work_sync(&acm->work);
  83 -       cancel_work_sync(&acm->waker);
  84  }
  85
  86  static void acm_disconnect(struct usb_interface *intf)
  87 @@ -1435,6 +1420,7 @@ static int acm_suspend(struct usb_interf
  88  static int acm_resume(struct usb_interface *intf)
  89  {
  90         struct acm *acm = usb_get_intfdata(intf);
  91 +       struct acm_wb *wb;
  92         int rv = 0;
  93         int cnt;
  94
  95 @@ -1449,6 +1435,21 @@ static int acm_resume(struct usb_interfa
  96         mutex_lock(&acm->mutex);
  97         if (acm->port.count) {
  98                 rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
  99 +
 100 +               spin_lock_irq(&acm->write_lock);
 101 +               if (acm->delayed_wb) {
 102 +                       wb = acm->delayed_wb;
 103 +                       acm->delayed_wb = NULL;
 104 +                       spin_unlock_irq(&acm->write_lock);
 105 +                       acm_start_wb(acm, acm->delayed_wb);
 106 +               } else {
 107 +                       spin_unlock_irq(&acm->write_lock);
 108 +               }
 109 +
 110 +               /*
 111 +                * delayed error checking because we must
 112 +                * do the write path at all cost
 113 +                */
 114                 if (rv < 0)
 115                         goto err_out;
 116
 117 --- a/drivers/usb/class/cdc-acm.h
 118 +++ b/drivers/usb/class/cdc-acm.h
 119 @@ -112,7 +112,6 @@ struct acm {
 120         struct mutex mutex;
 121         struct usb_cdc_line_coding line;                /* bits, stop, parity */
 122         struct work_struct work;                        /* work queue entry for line discipline waking up */
 123 -       struct work_struct waker;
 124         wait_queue_head_t drain_wait;                   /* close processing */
 125         struct tasklet_struct urb_task;                 /* rx processing */
 126         spinlock_t throttle_lock;                       /* synchronize throtteling and read callback */