On Friday 18 March 2011 14:03:43 Daniele Capuano wrote:
> A little update.
> It seems that the gadget itself has a strange behavior: I start
> monitoring the usb transfers using usbmon.
> My setup has remained the same, but NUM_ISO_PACKETS is 32. I also
> tryed, as Hans suggested, to submit two urbs in order to achieve
> double buffering, but nothing changed.
> I attach a little view of the usbmon output. As you can see, the first
> packet (second line) is received correctly, even though 1024 bytes are
> received while a packet of 512 bytes was requested by the host. After
> such receipt, nothing more is received.
> From the gadget, I monitored the callback calls, and I noticed that
> the callback is continuously called, even before the host submit the
> first urb. Maybe this means that zero-length packets are sent all the
> time before the host's first request. But what about the strange
> behavior after the host's requests? A first data buffer is sent, but
> then nothing more... it's seems quite strange to me...
Hi,
What speed is your device?
Try using "bInterval = 1" on the device side.
.bInterval = 6,
It might be there is a bug in the hardware driver for the gadget side. What
hardware driver are you using in your Linux kernel for the gadget side?
--HPS
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