libftdi Archives

Subject: Re: FT232H oddities in avrdude

From: Uwe Bonnes <bon@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
To: libftdi@xxxxxxxxxxxxxxxxxxxxxxx
Date: Thu, 15 Sep 2011 16:36:50 +0200
>>>>> "Joerg" == Joerg Wunsch <libftdi@xxxxxxxxxxxxxxxxx> writes:

    Joerg> In article
    Joerg> <CAGjSPUA02jW9bdMLnvGbRBS_0+LHVvZ9mzwR8Hh=UXsR0LTr4g@xxxxxxxxxxxxxx>
    Joerg> you write:
    >> This is a good point. The code will probably need to detect the
    >> current speed (which is only added to libusb-1.0 git recently)
    >> http://git.libusb.org/?p=libusb-stuge.git;a=summary;js=1 or current
    >> max packet size (512B in high speed mode, 64B in full speed mode).

    Joerg> I thought I've already seen something where it detects the max
    Joerg> packet size. 

 _ftdi_determine_max_packet_size() first looks at the device and then at
descriptor.endpoint[0].wMaxPacketSize. The latter is taken uncinditionally,
but if it is not found or the way to read it is not found, the chip default
is taken.

I suspect FreeBSD behaves other than our code expects and so we keep the
default on FreeBSD. Some print message after 
packet_size = descriptor.endpoint[0].wMaxPacketSize;
could confirm. 

Bye
-- 
Uwe Bonnes                bon@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

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