regmap: debugfs: Remove scratch buffer for register length calculation

[firefly-linux-kernel-4.4.55.git] / drivers / base / regmap / regmap-debugfs.c

diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index f42f2bac646623fc1db767bae3a5fff0ecf98aac..4a4737887ccec28ca2ee562ba73469a0e6e828df 100644 (file)
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -30,10 +30,9 @@ 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)
+static size_t regmap_calc_reg_len(int max_val)
 {
-       snprintf(buf, buf_size, "%x", max_val);
-       return strlen(buf);
+       return snprintf(NULL, 0, "%x", max_val);
 }
 
 static ssize_t regmap_name_read_file(struct file *file,
@@ -174,8 +173,7 @@ static inline void regmap_calc_tot_len(struct regmap *map,
 {
        /* Calculate the length of a fixed format  */
        if (!map->debugfs_tot_len) {
-               map->debugfs_reg_len = regmap_calc_reg_len(map->max_register,
-                                                          buf, count);
+               map->debugfs_reg_len = regmap_calc_reg_len(map->max_register),
                map->debugfs_val_len = 2 * map->format.val_bytes;
                map->debugfs_tot_len = map->debugfs_reg_len +
                        map->debugfs_val_len + 3;      /* : \n */
@@ -421,7 +419,7 @@ static ssize_t regmap_access_read_file(struct file *file,
                return -ENOMEM;
 
        /* Calculate the length of a fixed format  */
-       reg_len = regmap_calc_reg_len(map->max_register, buf, count);
+       reg_len = regmap_calc_reg_len(map->max_register);
        tot_len = reg_len + 10; /* ': R W V P\n' */
 
        for (i = 0; i <= map->max_register; i += map->reg_stride) {
@@ -432,7 +430,7 @@ static ssize_t regmap_access_read_file(struct file *file,
                /* If we're in the region the user is trying to read */
                if (p >= *ppos) {
                        /* ...but not beyond it */
-                       if (buf_pos >= count - 1 - tot_len)
+                       if (buf_pos + tot_len + 1 >= count)
                                break;
 
                        /* Format the register */