USB: use DIV_ROUND_UP

The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /
(d)) but is perhaps more readable.

An extract of the semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@haskernel@
@@

#include <linux/kernel.h>

@depends on haskernel@
expression n,d;
@@

(
- (n + d - 1) / d
+ DIV_ROUND_UP(n,d)
|
- (n + (d - 1)) / d
+ DIV_ROUND_UP(n,d)
)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP((n),d)
+ DIV_ROUND_UP(n,d)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP(n,(d))
+ DIV_ROUND_UP(n,d)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 4643212eb959..496c0c93ad81 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1406,7 +1406,7 @@ static void ftdi_write_bulk_callback (struct urb *urb)
         data_offset = priv->write_offset;
         if (data_offset > 0) {
                 /* Subtract the control bytes */
-                countback -= (data_offset * ((countback + (PKTSZ - 1)) / PKTSZ));
+                countback -= (data_offset * DIV_ROUND_UP(countback, PKTSZ));
         }
         spin_lock_irqsave(&priv->tx_lock, flags);
         --priv->tx_outstanding_urbs;
@@ -1506,7 +1506,7 @@ static void ftdi_read_bulk_callback (struct urb *urb)
 
         /* count data bytes, but not status bytes */
         countread = urb->actual_length;
-        countread -= 2 * ((countread + (PKTSZ - 1)) / PKTSZ);
+        countread -= 2 * DIV_ROUND_UP(countread, PKTSZ);
         spin_lock_irqsave(&priv->rx_lock, flags);
         priv->rx_bytes += countread;
         spin_unlock_irqrestore(&priv->rx_lock, flags);