target/linux/ipq806x/patches-4.4/009-7-watchdog-Drop-pointer-to-watchdog-device-from-struct-watchdog_device.patch

   1 From 0254e953537c92df3e7d0176f401a211e944fd61 Mon Sep 17 00:00:00 2001
   2 From: Guenter Roeck <linux@roeck-us.net>
   3 Date: Sun, 3 Jan 2016 15:11:58 -0800
   4 Subject: watchdog: Drop pointer to watchdog device from struct watchdog_device
   5
   6 The lifetime of the watchdog device pointer is different from the lifetime
   7 of its character device. Remove it entirely to avoid race conditions.
   8
   9 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  10 Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  11 Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
  12 ---
  13  Documentation/watchdog/watchdog-kernel-api.txt | 2 --
  14  drivers/watchdog/watchdog_core.c               | 8 ++++----
  15  drivers/watchdog/watchdog_dev.c                | 9 ++++-----
  16  include/linux/watchdog.h                       | 2 --
  17  4 files changed, 8 insertions(+), 13 deletions(-)
  18
  19 --- a/Documentation/watchdog/watchdog-kernel-api.txt
  20 +++ b/Documentation/watchdog/watchdog-kernel-api.txt
  21 @@ -44,7 +44,6 @@ The watchdog device structure looks like
  22
  23  struct watchdog_device {
  24         int id;
  25 -       struct device *dev;
  26         struct device *parent;
  27         const struct watchdog_info *info;
  28         const struct watchdog_ops *ops;
  29 @@ -65,7 +64,6 @@ It contains following fields:
  30    /dev/watchdog0 cdev (dynamic major, minor 0) as well as the old
  31    /dev/watchdog miscdev. The id is set automatically when calling
  32    watchdog_register_device.
  33 -* dev: device under the watchdog class (created by watchdog_register_device).
  34  * parent: set this to the parent device (or NULL) before calling
  35    watchdog_register_device.
  36  * info: a pointer to a watchdog_info structure. This structure gives some
  37 --- a/drivers/watchdog/watchdog_core.c
  38 +++ b/drivers/watchdog/watchdog_core.c
  39 @@ -249,8 +249,8 @@ static int __watchdog_register_device(st
  40
  41                 ret = register_reboot_notifier(&wdd->reboot_nb);
  42                 if (ret) {
  43 -                       dev_err(wdd->dev, "Cannot register reboot notifier (%d)\n",
  44 -                               ret);
  45 +                       pr_err("watchdog%d: Cannot register reboot notifier (%d)\n",
  46 +                              wdd->id, ret);
  47                         watchdog_dev_unregister(wdd);
  48                         ida_simple_remove(&watchdog_ida, wdd->id);
  49                         return ret;
  50 @@ -262,8 +262,8 @@ static int __watchdog_register_device(st
  51
  52                 ret = register_restart_handler(&wdd->restart_nb);
  53                 if (ret)
  54 -                       dev_warn(wdd->dev, "Cannot register restart handler (%d)\n",
  55 -                                ret);
  56 +                       pr_warn("watchog%d: Cannot register restart handler (%d)\n",
  57 +                               wdd->id, ret);
  58         }
  59
  60         return 0;
  61 --- a/drivers/watchdog/watchdog_dev.c
  62 +++ b/drivers/watchdog/watchdog_dev.c
  63 @@ -143,7 +143,8 @@ static int watchdog_stop(struct watchdog
  64                 return 0;
  65
  66         if (test_bit(WDOG_NO_WAY_OUT, &wdd->status)) {
  67 -               dev_info(wdd->dev, "nowayout prevents watchdog being stopped!\n");
  68 +               pr_info("watchdog%d: nowayout prevents watchdog being stopped!\n",
  69 +                       wdd->id);
  70                 return -EBUSY;
  71         }
  72
  73 @@ -604,7 +605,7 @@ static int watchdog_release(struct inode
  74
  75         /* If the watchdog was not stopped, send a keepalive ping */
  76         if (err < 0) {
  77 -               dev_crit(wdd->dev, "watchdog did not stop!\n");
  78 +               pr_crit("watchdog%d: watchdog did not stop!\n", wdd->id);
  79                 watchdog_ping(wdd);
  80         }
  81
  82 @@ -750,7 +751,6 @@ int watchdog_dev_register(struct watchdo
  83                 watchdog_cdev_unregister(wdd);
  84                 return PTR_ERR(dev);
  85         }
  86 -       wdd->dev = dev;
  87
  88         return ret;
  89  }
  90 @@ -765,8 +765,7 @@ int watchdog_dev_register(struct watchdo
  91
  92  void watchdog_dev_unregister(struct watchdog_device *wdd)
  93  {
  94 -       device_destroy(&watchdog_class, wdd->dev->devt);
  95 -       wdd->dev = NULL;
  96 +       device_destroy(&watchdog_class, wdd->wd_data->cdev.dev);
  97         watchdog_cdev_unregister(wdd);
  98  }
  99
 100 --- a/include/linux/watchdog.h
 101 +++ b/include/linux/watchdog.h
 102 @@ -55,7 +55,6 @@ struct watchdog_ops {
 103  /** struct watchdog_device - The structure that defines a watchdog device
 104   *
 105   * @id:                The watchdog's ID. (Allocated by watchdog_register_device)
 106 - * @dev:       The device for our watchdog
 107   * @parent:    The parent bus device
 108   * @info:      Pointer to a watchdog_info structure.
 109   * @ops:       Pointer to the list of watchdog operations.
 110 @@ -82,7 +81,6 @@ struct watchdog_ops {
 111   */
 112  struct watchdog_device {
 113         int id;
 114 -       struct device *dev;
 115         struct device *parent;
 116         const struct watchdog_info *info;
 117         const struct watchdog_ops *ops;