From a52eaeb1898bc0589888ee62de291aa278379004 Mon Sep 17 00:00:00 2001 From: Tero Kristo Date: Thu, 24 Oct 2013 15:03:41 +0300 Subject: regmap: debugfs: Fix a boot time crash with early regmap init If called early enough, regmap_debugfs_init causes a crash, if the fs subsystem does not have its mount cache created yet. Even if this would work, the root node for the regmap debugfs is still missing, thus postpone the regmap_debugfs_init in this case until the root node is created. A special regmap_debugfs_early list is created for this purpose which is parsed later in the boot. Signed-off-by: Tero Kristo Signed-off-by: Mark Brown --- drivers/base/regmap/regmap-debugfs.c | 57 ++++++++++++++++++++++++++++++++---- 1 file changed, 52 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index de11ecaf3833..c5471cd6ebb7 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -15,10 +15,19 @@ #include #include #include +#include #include "internal.h" +struct regmap_debugfs_node { + struct regmap *map; + const char *name; + struct list_head link; +}; + static struct dentry *regmap_debugfs_root; +static LIST_HEAD(regmap_debugfs_early_list); +static DEFINE_MUTEX(regmap_debugfs_early_lock); /* Calculate the length of a fixed format */ static size_t regmap_calc_reg_len(int max_val, char *buf, size_t buf_size) @@ -465,6 +474,20 @@ void regmap_debugfs_init(struct regmap *map, const char *name) struct rb_node *next; struct regmap_range_node *range_node; + /* If we don't have the debugfs root yet, postpone init */ + if (!regmap_debugfs_root) { + struct regmap_debugfs_node *node; + node = kzalloc(sizeof(*node), GFP_KERNEL); + if (!node) + return; + node->map = map; + node->name = name; + mutex_lock(®map_debugfs_early_lock); + list_add(&node->link, ®map_debugfs_early_list); + mutex_unlock(®map_debugfs_early_lock); + return; + } + INIT_LIST_HEAD(&map->debugfs_off_cache); mutex_init(&map->cache_lock); @@ -519,18 +542,42 @@ void regmap_debugfs_init(struct regmap *map, const char *name) void regmap_debugfs_exit(struct regmap *map) { - debugfs_remove_recursive(map->debugfs); - mutex_lock(&map->cache_lock); - regmap_debugfs_free_dump_cache(map); - mutex_unlock(&map->cache_lock); - kfree(map->debugfs_name); + if (map->debugfs) { + debugfs_remove_recursive(map->debugfs); + mutex_lock(&map->cache_lock); + regmap_debugfs_free_dump_cache(map); + mutex_unlock(&map->cache_lock); + kfree(map->debugfs_name); + } else { + struct regmap_debugfs_node *node, *tmp; + + mutex_lock(®map_debugfs_early_lock); + list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list, + link) { + if (node->map == map) { + list_del(&node->link); + kfree(node); + } + } + mutex_unlock(®map_debugfs_early_lock); + } } void regmap_debugfs_initcall(void) { + struct regmap_debugfs_node *node, *tmp; + regmap_debugfs_root = debugfs_create_dir("regmap", NULL); if (!regmap_debugfs_root) { pr_warn("regmap: Failed to create debugfs root\n"); return; } + + mutex_lock(®map_debugfs_early_lock); + list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list, link) { + regmap_debugfs_init(node->map, node->name); + list_del(&node->link); + kfree(node); + } + mutex_unlock(®map_debugfs_early_lock); } -- cgit v1.2.3