video/via: Convert to kstrtou8_from_user

This patch replaces the code for getting an number from a
userspace buffer by a simple call to kstrou8_from_user.
This makes it easier to read and less error prone.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

1 files changed, 12 insertions, 22 deletions

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index 0c8837565bc..c80e770e180 100644
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -1276,17 +1276,12 @@ static int viafb_dfph_proc_open(struct inode *inode, struct file *file)
 static ssize_t viafb_dfph_proc_write(struct file *file,
         const char __user *buffer, size_t count, loff_t *pos)
 {
-        char buf[20];
-        u8 reg_val = 0;
-        unsigned long length;
-        if (count < 1)
-                return -EINVAL;
-        length = count > 20 ? 20 : count;
-        if (copy_from_user(&buf[0], buffer, length))
-                return -EFAULT;
-        buf[length - 1] = '\0'; /*Ensure end string */
-        if (kstrtou8(buf, 0, &reg_val) < 0)
-                return -EINVAL;
+        int err;
+        u8 reg_val;
+        err = kstrtou8_from_user(buffer, count, 0, &reg_val);
+        if (err)
+                return err;
+
         viafb_write_reg_mask(CR97, VIACR, reg_val, 0x0f);
         return count;
 }
@@ -1316,17 +1311,12 @@ static int viafb_dfpl_proc_open(struct inode *inode, struct file *file)
 static ssize_t viafb_dfpl_proc_write(struct file *file,
         const char __user *buffer, size_t count, loff_t *pos)
 {
-        char buf[20];
-        u8 reg_val = 0;
-        unsigned long length;
-        if (count < 1)
-                return -EINVAL;
-        length = count > 20 ? 20 : count;
-        if (copy_from_user(&buf[0], buffer, length))
-                return -EFAULT;
-        buf[length - 1] = '\0'; /*Ensure end string */
-        if (kstrtou8(buf, 0, &reg_val) < 0)
-                return -EINVAL;
+        int err;
+        u8 reg_val;
+        err = kstrtou8_from_user(buffer, count, 0, &reg_val);
+        if (err)
+                return err;
+
         viafb_write_reg_mask(CR99, VIACR, reg_val, 0x0f);
         return count;
 }