regcache: Make sure we sync register 0 in an rbtree cache

[sfrench/cifs-2.6.git] / drivers / base / regmap / regcache-rbtree.c

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index e31498499b0fdc86df83b653950769ec6c814e31..861ad2c81dff580fbf309f2b6eece8f15e1d769b 100644 (file)
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -11,12 +11,15 @@
  */
 
 #include <linux/slab.h>
+#include <linux/debugfs.h>
 #include <linux/rbtree.h>
+#include <linux/seq_file.h>
 
 #include "internal.h"
 
 static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
                                 unsigned int value);
+static int regcache_rbtree_exit(struct regmap *map);
 
 struct regcache_rbtree_node {
        /* the actual rbtree node holding this block */
@@ -124,6 +127,60 @@ static int regcache_rbtree_insert(struct rb_root *root,
        return 1;
 }
 
+#ifdef CONFIG_DEBUG_FS
+static int rbtree_show(struct seq_file *s, void *ignored)
+{
+       struct regmap *map = s->private;
+       struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
+       struct regcache_rbtree_node *n;
+       struct rb_node *node;
+       unsigned int base, top;
+       int nodes = 0;
+       int registers = 0;
+
+       mutex_lock(&map->lock);
+
+       for (node = rb_first(&rbtree_ctx->root); node != NULL;
+            node = rb_next(node)) {
+               n = container_of(node, struct regcache_rbtree_node, node);
+
+               regcache_rbtree_get_base_top_reg(n, &base, &top);
+               seq_printf(s, "%x-%x (%d)\n", base, top, top - base + 1);
+
+               nodes++;
+               registers += top - base + 1;
+       }
+
+       seq_printf(s, "%d nodes, %d registers, average %d registers\n",
+                  nodes, registers, registers / nodes);
+
+       mutex_unlock(&map->lock);
+
+       return 0;
+}
+
+static int rbtree_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, rbtree_show, inode->i_private);
+}
+
+static const struct file_operations rbtree_fops = {
+       .open           = rbtree_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+static void rbtree_debugfs_init(struct regmap *map)
+{
+       debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
+}
+#else
+static void rbtree_debugfs_init(struct regmap *map)
+{
+}
+#endif
+
 static int regcache_rbtree_init(struct regmap *map)
 {
        struct regcache_rbtree_ctx *rbtree_ctx;
@@ -146,10 +203,12 @@ static int regcache_rbtree_init(struct regmap *map)
                        goto err;
        }
 
+       rbtree_debugfs_init(map);
+
        return 0;
 
 err:
-       regcache_exit(map);
+       regcache_rbtree_exit(map);
        return ret;
 }
 
@@ -318,7 +377,7 @@ static int regcache_rbtree_sync(struct regmap *map)
 
                        /* Is this the hardware default?  If so skip. */
                        ret = regcache_lookup_reg(map, i);
-                       if (ret > 0 && val == map->reg_defaults[ret].def)
+                       if (ret >= 0 && val == map->reg_defaults[ret].def)
                                continue;
 
                        map->cache_bypass = 1;