clk: Don't hold prepare_lock across debugfs creation

author Stephen Boyd <sboyd@codeaurora.org>

Fri, 5 Sep 2014 06:37:49 +0000 (23:37 -0700)

committer Mike Turquette <mturquette@linaro.org>

Wed, 10 Sep 2014 21:36:20 +0000 (14:36 -0700)
author Stephen Boyd <sboyd@codeaurora.org>
Fri, 5 Sep 2014 06:37:49 +0000 (23:37 -0700)
committer Mike Turquette <mturquette@linaro.org>
Wed, 10 Sep 2014 21:36:20 +0000 (14:36 -0700)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c

index b76fa69b44cb7eb625c65723862ebc37d963b494..8ca28189e4e96444c366286b531ace80f5c763c9 100644 (file)
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -100,6 +100,8 @@ static void clk_enable_unlock(unsigned long flags)
  
  static struct dentry *rootdir;
  static int inited = 0;
+static DEFINE_MUTEX(clk_debug_lock);
+static HLIST_HEAD(clk_debug_list);
  
  static struct hlist_head *all_lists[] = {
         &clk_root_list,
@@ -300,28 +302,6 @@ out:
         return ret;
  }
  
-/* caller must hold prepare_lock */
-static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry)
-{
-       struct clk *child;
-       int ret = -EINVAL;;
-
-       if (!clk || !pdentry)
-               goto out;
-
-       ret = clk_debug_create_one(clk, pdentry);
-
-       if (ret)
-               goto out;
-
-       hlist_for_each_entry(child, &clk->children, child_node)
-               clk_debug_create_subtree(child, pdentry);
-
-       ret = 0;
-out:
-       return ret;
-}
-
  /**
   * clk_debug_register - add a clk node to the debugfs clk tree
   * @clk: the clk being added to the debugfs clk tree
@@ -329,20 +309,21 @@ out:
   * Dynamically adds a clk to the debugfs clk tree if debugfs has been
   * initialized.  Otherwise it bails out early since the debugfs clk tree
   * will be created lazily by clk_debug_init as part of a late_initcall.
- *
- * Caller must hold prepare_lock.  Only clk_init calls this function (so
- * far) so this is taken care.
   */
  static int clk_debug_register(struct clk *clk)
  {
         int ret = 0;
  
+       mutex_lock(&clk_debug_lock);
+       hlist_add_head(&clk->debug_node, &clk_debug_list);
+
         if (!inited)
-               goto out;
+               goto unlock;
  
-       ret = clk_debug_create_subtree(clk, rootdir);
+       ret = clk_debug_create_one(clk, rootdir);
+unlock:
+       mutex_unlock(&clk_debug_lock);
  
-out:
         return ret;
  }
  
@@ -353,12 +334,18 @@ out:
   * Dynamically removes a clk and all it's children clk nodes from the
   * debugfs clk tree if clk->dentry points to debugfs created by
   * clk_debug_register in __clk_init.
- *
- * Caller must hold prepare_lock.
   */
  static void clk_debug_unregister(struct clk *clk)
  {
+       mutex_lock(&clk_debug_lock);
+       if (!clk->dentry)
+               goto out;
+
+       hlist_del_init(&clk->debug_node);
         debugfs_remove_recursive(clk->dentry);
+       clk->dentry = NULL;
+out:
+       mutex_unlock(&clk_debug_lock);
  }
  
  struct dentry *clk_debugfs_add_file(struct clk *clk, char *name, umode_t mode,
@@ -415,17 +402,12 @@ static int __init clk_debug_init(void)
         if (!d)
                 return -ENOMEM;
  
-       clk_prepare_lock();
-
-       hlist_for_each_entry(clk, &clk_root_list, child_node)
-               clk_debug_create_subtree(clk, rootdir);
-
-       hlist_for_each_entry(clk, &clk_orphan_list, child_node)
-               clk_debug_create_subtree(clk, rootdir);
+       mutex_lock(&clk_debug_lock);
+       hlist_for_each_entry(clk, &clk_debug_list, debug_node)
+               clk_debug_create_one(clk, rootdir);
  
         inited = 1;
-
-       clk_prepare_unlock();
+       mutex_unlock(&clk_debug_lock);
  
         return 0;
  }
@@ -2087,14 +2069,16 @@ void clk_unregister(struct clk *clk)
  {
         unsigned long flags;
  
-       if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
-               return;
+       if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
+               return;
+
+       clk_debug_unregister(clk);
  
         clk_prepare_lock();
  
         if (clk->ops == &clk_nodrv_ops) {
                 pr_err("%s: unregistered clock: %s\n", __func__, clk->name);
-               goto out;
+               return;
         }
         /*
          * Assign empty clock ops for consumers that might still hold
@@ -2113,16 +2097,13 @@ void clk_unregister(struct clk *clk)
                         clk_set_parent(child, NULL);
         }
  
-       clk_debug_unregister(clk);
-
         hlist_del_init(&clk->child_node);
  
         if (clk->prepare_count)
                 pr_warn("%s: unregistering prepared clock: %s\n",
                                         __func__, clk->name);
-
         kref_put(&clk->ref, __clk_release);
-out:
+
         clk_prepare_unlock();
  }
  EXPORT_SYMBOL_GPL(clk_unregister);
diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h

index efbf70b9fd847f01fb5b623210ad60ee5dc54bdf..4ed34105c3718d11577e8fff44c92ce4b806493a 100644 (file)
--- a/include/linux/clk-private.h
+++ b/include/linux/clk-private.h
@@ -48,6 +48,7 @@ struct clk {
         unsigned long           accuracy;
         struct hlist_head       children;
         struct hlist_node       child_node;
+       struct hlist_node       debug_node;
         unsigned int            notifier_count;
  #ifdef CONFIG_DEBUG_FS
         struct dentry           *dentry;
author	Stephen Boyd <sboyd@codeaurora.org>
	Fri, 5 Sep 2014 06:37:49 +0000 (23:37 -0700)
committer	Mike Turquette <mturquette@linaro.org>
	Wed, 10 Sep 2014 21:36:20 +0000 (14:36 -0700)
drivers/clk/clk.c		patch \| blob \| blame \| history
include/linux/clk-private.h		patch \| blob \| blame \| history