On Freitag, 30. Juni 2017 05:49:56 CEST Bin Meng wrote:
Hi,
On Fri, Jun 23, 2017 at 5:54 PM, Bin Meng bmeng.cn@gmail.com wrote:
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@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;
You remove the initialization of dev->maxpacketsize here ...
if (do_read) {
[...]
*/ err = get_descriptor_len(dev, 64, 8); if (err) return err;
... and probably return early here. Can you add some debug output to get_descriptor_len(...) (len, expected len, return code)?
} else {if (dev->speed == USB_SPEED_LOW)dev->descriptor.bMaxPacketSize0 = 8;elsedev->descriptor.bMaxPacketSize0 = 64; } dev->epmaxpacketin[0] = dev->descriptor.bMaxPacketSize0;--
For some reason that I don't understand, this patch breaks EHCI. dev->maxpacketsize is equal to zero with this patch, which leads to a 'divide error' exception in ehci_submit_async(). Not sure if anyone has some hints?
For now, I will just drop this patch in v2. This needs be further revisited.
Kind regards,
Stefan