coh901318: don't open-code simple_read_from_buffer()

... and BTW, failing copy_to_user() means EFAULT, not EINVAL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 21 deletions

diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index 9bfaddd57ef1..31011d2a26fc 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -1339,15 +1339,14 @@ static int coh901318_debugfs_read(struct file *file, char __user *buf,
 {
         u64 started_channels = debugfs_dma_base->pm.started_channels;
         int pool_count = debugfs_dma_base->pool.debugfs_pool_counter;
-        int i;
-        int ret = 0;
         char *dev_buf;
         char *tmp;
-        int dev_size;
+        int ret;
+        int i;
 
         dev_buf = kmalloc(4*1024, GFP_KERNEL);
         if (dev_buf == NULL)
-                goto err_kmalloc;
+                return -ENOMEM;
         tmp = dev_buf;
 
         tmp += sprintf(tmp, "DMA -- enabled dma channels\n");
@@ -1357,26 +1356,11 @@ static int coh901318_debugfs_read(struct file *file, char __user *buf,
                         tmp += sprintf(tmp, "channel %d\n", i);
 
         tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count);
-        dev_size = tmp  - dev_buf;
-
-        /* No more to read if offset != 0 */
-        if (*f_pos > dev_size)
-                goto out;
 
-        if (count > dev_size - *f_pos)
-                count = dev_size - *f_pos;
-
-        if (copy_to_user(buf, dev_buf + *f_pos, count))
-                ret = -EINVAL;
-        ret = count;
-        *f_pos += count;
-
- out:
+        ret = simple_read_from_buffer(buf, count, f_pos, dev_buf, 
+                                        tmp - dev_buf);
         kfree(dev_buf);
         return ret;
-
- err_kmalloc:
-        return 0;
 }
 
 static const struct file_operations coh901318_debugfs_status_operations = {