Mar 05 2008

USB: use DIV_ROUND_UP 

Author: Julia Lawall <julia@diku.dk>

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/)

// 
@haskernel@
@@

#include 

@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)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman 


---
 drivers/usb/host/r8a66597-hcd.c | 6 +++---
 drivers/usb/misc/usbtest.c      | 2 +-
 drivers/usb/serial/ftdi_sio.c   | 4 ++--
 drivers/usb/serial/io_ti.c      | 2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)
 
diff --git a/drivers/usb/host/r8a66597-hcd.c b/drivers/usb/host/r8a66597-hcd.c
index 9f80e52..afd4fbe 100644
--- a/drivers/usb/host/r8a66597-hcd.c
+++ b/drivers/usb/host/r8a66597-hcd.c
@@ -960,9 +960,9 @@ static void prepare_packet_read(struct r8a66597 *r8a66597,
 				r8a66597_write(r8a66597, TRCLR,
 						td->pipe->pipetre);
 				r8a66597_write(r8a66597,
-						(urb->transfer_buffer_length
-						+ td->maxpacket - 1)
-						/ td->maxpacket,
+						DIV_ROUND_UP
+						  (urb->transfer_buffer_length,
+						   td->maxpacket),
 						td->pipe->pipetrn);
 				r8a66597_bset(r8a66597, TRENB,
 						td->pipe->pipetre);
diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index b6b5b2a..1710047 100644
--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -1404,7 +1404,7 @@ static struct urb *iso_alloc_urb (
 		return NULL;
 	maxp = 0x7ff & le16_to_cpu(desc->wMaxPacketSize);
 	maxp *= 1 + (0x3 & (le16_to_cpu(desc->wMaxPacketSize) >> 11));
-	packets = (bytes + maxp - 1) / maxp;
+	packets = DIV_ROUND_UP(bytes, maxp);
 
 	urb = usb_alloc_urb (packets, GFP_KERNEL);
 	if (!urb)
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 4643212..496c0c9 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);
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 39d71fd..6afee30 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -654,7 +654,7 @@ static void TIChasePort(struct edgeport_port *port, unsigned long timeout, int f
 	/* (TIIsTxActive doesn't seem to wait for the last byte) */
 	if ((baud_rate=port->baud_rate) == 0)
 		baud_rate = 50;
-	msleep(max(1,(10000+baud_rate-1)/baud_rate));
+	msleep(max(1, DIV_ROUND_UP(10000, baud_rate)));
 }
 
 static int TIChooseConfiguration (struct usb_device *dev)

qlambert