[U-Boot] [PATCH 03/16] usb: Remove unnecessary work in usb_setup_descriptor()

[Bin Meng]

The only work we need do in usb_setup_descriptor() is to initialize
dev->descriptor.bMaxPacketSize0, when do_read is false. Other steps
are the same as do_read being true.

While we are here, update the comment block to be within 80 cols.

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
---

 common/usb.c | 40 ++++++++++++++++++----------------------
 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/common/usb.c b/common/usb.c
index 15e1e4c..293d968 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -962,37 +962,33 @@ static int usb_setup_descriptor(struct usb_device *dev, bool do_read)
 	 * some more, or keeps on retransmitting the 8 byte header.
 	 */
 
-	if (dev->speed == USB_SPEED_LOW) {
-		dev->descriptor.bMaxPacketSize0 = 8;
-		dev->maxpacketsize = PACKET_SIZE_8;
-	} else {
-		dev->descriptor.bMaxPacketSize0 = 64;
-		dev->maxpacketsize = PACKET_SIZE_64;
-	}
-	dev->epmaxpacketin[0] = dev->descriptor.bMaxPacketSize0;
-	dev->epmaxpacketout[0] = dev->descriptor.bMaxPacketSize0;
-
 	if (do_read) {
 		int err;
 
 		/*
-		 * Validate we've received only at least 8 bytes, not that we've
-		 * received the entire descriptor. The reasoning is:
-		 * - The code only uses fields in the first 8 bytes, so that's all we
-		 *   need to have fetched at this stage.
-		 * - The smallest maxpacket size is 8 bytes. Before we know the actual
-		 *   maxpacket the device uses, the USB controller may only accept a
-		 *   single packet. Consequently we are only guaranteed to receive 1
-		 *   packet (at least 8 bytes) even in a non-error case.
+		 * Validate we've received only at least 8 bytes, not that
+		 * we've received the entire descriptor. The reasoning is:
+		 * - The code only uses fields in the first 8 bytes, so that's
+		 *   all we need to have fetched at this stage.
+		 * - The smallest maxpacket size is 8 bytes. Before we know
+		 *   the actual maxpacket the device uses, the USB controller
+		 *   may only accept a single packet. Consequently we are only
+		 *   guaranteed to receive 1 packet (at least 8 bytes) even in
+		 *   a non-error case.
 		 *
-		 * At least the DWC2 controller needs to be programmed with the number
-		 * of packets in addition to the number of bytes. A request for 64
-		 * bytes of data with the maxpacket guessed as 64 (above) yields a
-		 * request for 1 packet.
+		 * At least the DWC2 controller needs to be programmed with
+		 * the number of packets in addition to the number of bytes.
+		 * A request for 64 bytes of data with the maxpacket guessed
+		 * as 64 (above) yields a request for 1 packet.
 		 */
 		err = get_descriptor_len(dev, 64, 8);
 		if (err)
 			return err;
+	} else {
+		if (dev->speed == USB_SPEED_LOW)
+			dev->descriptor.bMaxPacketSize0 = 8;
+		else
+			dev->descriptor.bMaxPacketSize0 = 64;
 	}
 
 	dev->epmaxpacketin[0] = dev->descriptor.bMaxPacketSize0;
-- 
2.9.2