Re: [avrdude-dev] Fwd: FTDI flashing stops at different positions

[Hannes Weisbach]

Am 19.07.2012 um 22:26 schrieb Daniel Schulz:

> ---------- Forwarded message ----------
> From: Daniel Schulz <address@hidden>
> Date: 2012/7/19
> Subject: Re: [avrdude-dev] FTDI flashing stops at different positions
> 
> 
> 
> Yes, sorry.
> Now I can reproduce the behavior. If I flash with -vvvv (it worked
> sometimes with -vv or even -vvv) then it will go through the whole
> process. It doesnt matter, if I restarted the PC or not. If I turn the
> -vvvv of, it stops again at 97%.
> Idont really know what to do. Should I buy a "real" flashing device?
> Or what can you recommend?
Since your issues seem to be timing related, I don't think anymore your problem 
relates to the infinite loop I was talking about.
> 
> Ah, additionally I've tried to get a log, but there is only a
> FTDI LOG: 80 20 fb 82 00 00
> FTDI LOG: 80 60 fb 82 00 00
> repeatedly in the file. Is this right?!
No. there should be more. This is only the flashing of the programming led (for 
the standard avrftdi configuration).
> My command line looked like this:
> avrdude -p m8 -c avrftdi -b 1000000 -U
> flash:w:/home/daniel/ng/quax/17a410_i2c_r08/hex/bl-17a_p40_m1.hex:a
> -vvvv >avrdude_quax.log
As I said, -b 1000000 is too fast. The additional output on the terminal slows 
the program down. Try -b 10000.

Ha! By browsing through the source, I think I found the source of your problem:
Someone committed a faulty flush-routine, which cleans buffers instead of 
flushing them ("ftdi_usb_purge_buffers()"). If you set your programming speed 
too high, data in transfer buffers will be deleted by this call (instead of 
being pushed to the AVR). This is the reason why -vvvv helps - it slows the 
program flow down, because the program has to do terminal I/O. You can choose a 
lower frequency (10kHz should be fine). At worst you have to keep -vvvv on :(
I have the fix for this ready too. I will submit it in the next week or so.

Best regards,
Hannes