Re: [libusb] Zero Length Packet Issue

[Chermak, D. <dal...@ph...>]

Thanks Alan!

Looks like usbmon is not present in the OS build running on the TI EVM. I will have to build and deploy it myself.

I hooked up the USB analyzer and the ZLP is being sent by the FX2 on EP6 right after the 131st 0x220 byte DATA1 packet. No additional data is sent on EP6, so I have no idea where the additional 3KB of data in the libusb transfer buffer came from.

Regards,

Dale

-----Original Message-----
From: Alan Stern [mailto:st...@ro...]
Sent: Friday, March 21, 2014 12:46 PM
To: Chermak, Dale
Cc: Libusb Mailing List
Subject: Re: [libusb] Zero Length Packet Issue

On Fri, 21 Mar 2014, Chermak, Dale wrote:

> You need to use a USB analyzer to see whether the device actually sent a ZLP.  That's the only way to determine whether the problem is in the FX2 or in the driver stack.
>
> I'll get that hooked up this afternoon, though I suspect I will see the ZLP being sent.

In addition, since you have a Linux-based host, you can use usbmon to see what the host thinks it is receiving.  Instructions are in the kernel source file Documentation/usb/usbmon.txt.

Alan Stern


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