greybus: es1: move debugfs function to use kstrotoint_from_user()

No need to duplicate built-in functions that the kernel has, so have the
core kernel parse the userspace string.  Saves us an allocation and
makes the logic simpler.

Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

diff --git a/drivers/staging/greybus/es1.c b/drivers/staging/greybus/es1.c
index 796c2ab..a7fb4b5 100644 (file)
--- a/drivers/staging/greybus/es1.c
+++ b/drivers/staging/greybus/es1.c
@@ -581,20 +581,19 @@ static ssize_t apb1_log_enable_write(struct file *f, const char __user *buf,
                                size_t count, loff_t *ppos)
 {
        int enable;
-       char *tmp_buf;
-       ssize_t retval = -EINVAL;
+       ssize_t retval;
        struct es1_ap_dev *es1 = (struct es1_ap_dev *)f->f_inode->i_private;
 
-       tmp_buf = kmalloc(count, GFP_KERNEL);
-       if (!tmp_buf)
-               return -ENOMEM;
+       retval = kstrtoint_from_user(buf, count, 10, &enable);
+       if (retval)
+               return retval;
 
-       copy_from_user(tmp_buf, buf, count);
-       if (sscanf(tmp_buf, "%d", &enable) == 1) {
+       if (enable) {
                usb_log_enable(es1, enable);
                retval = count;
+       } else {
+               retval = -EINVAL;
        }
-       kfree(tmp_buf);
 
        return retval;
 }