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Date: Mon, 06 Oct 2014 13:11:45 +0200
From: Hans Petter Selasky <hps@selasky.org>
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To: lev@FreeBSD.org, freebsd-usb@freebsd.org, 
 "libusb-devel@lists.sourceforge.net" <libusb-devel@lists.sourceforge.net>
Subject: Re: Is here maximum size of buffer for libusb_fill_bulk_transfer()
 call?
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On 10/06/14 13:06, Lev Serebryakov wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA512
>
> On 06.10.2014 15:03, Hans Petter Selasky wrote:
>
>>> Is here practical buffer size limit? I mean, maybe, standard
>>> limits transfer size by 64K or something like this?
>>
>> If the transfer is too big, libusb in FreeBSD loops using an
>> internal buffer, unlike Linux. You should be able to setup any
>> positive length which fits into an integer of type "int" or
>> "uint32_t".
>   My question is more about cross-platform behavior, as I try to write
> cross-platform project.
>

Hi,

In Linux you should not transmit more than 16Kbytes at a time for BULK 
at HighSpeed, from what I know. Might have been fixed recently though.

--HPS