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...@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
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