[U-Boot] [PATCH v3 9/9] dfu: Support larger than memory transfers.

[Lukasz Majewski]

Hi Tom,

First of all, sorry for late reply.

> On Mon, Feb 18, 2013 at 11:01:42AM +0100, Lukasz Majewski wrote:
> > Hi Tom,
> > 
> > > On Fri, Nov 30, 2012 at 08:01:12PM +0200, Pantelis Antoniou wrote:
> > > 
> > > > We didn't support upload/download larger than available memory.
> > > > This is pretty bad when you have to update your root filesystem
> > > > for example.
> > > > 
> > > > This patch removes the limitation (and the crashes when you
> > > > transfered any file larger than 4MB).
> > > > On top of that reduces the huge dfu buffer from 4MB to just 64K,
> > > > which was over the top.
> > > > 
> > > > The sequence number is a 16 bit counter; make sure we
> > > > handle rollover correctly. This fixes the wrong transfers for
> > > > large (> 256MB) images.
> > > > 
> > > > Also utilize a variable to handle initialization, so that we
> > > > don't rely on just the counter sent by the host.
> > > > 
> > > > Signed-off-by: Pantelis Antoniou <panto at antoniou-consulting.com>
> > > 
> > > To be clear, patches 1-8 are good and we should take, but this one
> > > means we can't use FAT/EXT* partitions without more work.  I would
> > > suggest that we set this part aside for a moment and perhaps limit
> > > transfers that are larget than RAM to RAW only where we can write
> > > in chunks today.
> > > 
> > 
> > As fair as I remember, some additional work needs to be done with
> > composite.c file (to remove nasty #ifdefs). There was a problem with
> > newer version of dfu-utils (new handling of descriptors). 
> 
> I see you and Pantelis talking about if some changes were really
> needed in composite.c or not, but nothing about dfu-utils. 

Changes in composite.c (adding some #ifdefs) were made because dfu-util
developers made the significant change in descriptors handling between
dfu-utils ver. 0.1 (which I've been using on my antic/test machine
debian) and the newest dfu-utils (which Pantelis was using, and which
is now available on recent debian).

To be honest the current DFU code (v2013.01) works with the dfu-utils
ver 0.1 (the old one). It breaks with new one.


> Were you
> objecting to the composite.c changes because you didn't need them, or
> because they in turn broke trats (can I get one of these somewhere?)

I'm objecting to adding a "quick hack style" #ifdefs to generic
composite.c code. As fair as I remember this corrected code works with
DFU, but I'd need to check if those composite.c changes will not break
the UMS patches posted recently.

Regarding TRATS: It is an official Tizen development board (mobile
phone):
http://www.youtube.com/watch?v=ya7ucT1wzOA

It was distributed on some fair show, but I cannot tell how to obtain
one.

> The only other unresolved thing was about board_usb_init() which I
> think was settled on trats needing to change behavior.

As fair as I remember trats follows u-boot policy to enable things only
when they are really needed.
But I will not be stubborn here. On the end I might end up with a weak
function (or enabling USB by default). I think, that this is a minor
issue when compared to composite.c


My proposition:
- Now we have middle of Feb, we can add Pantelis Patches, UMS patches
  to u-boot tree (from Marek's USB tree) and fix conflicts up till
  v2013.03 release. I can point two big sets of patches (related only to
  Samsung boards) floating around without a common "base": Pantelis DFU
  work and UMS support patches.

- I plan to work on composite/DFU (and potential UMS problems) at next
  week (up Friday I'm totally buried with other work)

-- 
Best regards,

Lukasz Majewski

Samsung R&D Poland (SRPOL) | Linux Platform Group