[U-Boot] [PATCH v2] fastboot: OUT transaction length must be aligned to wMaxPacketSize

[Marek Vasut]

On 04/06/2016 09:09 AM, Lukasz Majewski wrote:
> Hi Steve, Marek, Sam
> 
>> On Apr 5, 2016 3:07 PM, "Marek Vasut" <marex at denx.de> wrote:
>>>
>>> On 04/05/2016 08:31 PM, Steve Rae wrote:
>>>> commit 9e4b510 fastboot: OUT transaction length must be aligned to
>> wMaxPacketSize
>>>> breaks some boards...
>>>>
>>>> Therefore add a conditional Kconfig to optionally enable this
>>>> feature.
>>>
>>> Did you drill into it to figure out why this is needed ?
>>>
>>
>> Marek,
>> Let me clarify....
>> All my boards work with the original code (before the commit which
>> aligned the size to the wMaxPacketSize).... Since that commit, all my
>> boards are broken.
>> And you will notice in this patch, that none of my boards define this
>> CONFIG_ ...
> 
> Guys, please correct me if I'm wrong, but the problem _is_ be caused
> by supporting different fastboot protocol versions.
> 
> Unfortunately, there is no way to specify "version" in the protocol so
> different versions of fastboot application handle transmission
> differently.
> 
> I think that Sam and Steve were trying to test the code by using their
> fastboot apps, but without any conclusion. Am I right there? Has
> something changed?
> 
> I'm OK with Kconfig flag approach, if we don't have any reliable way to
> distinct protocol versions.
> 
> One fastboot user my try it with this option enabled or disabled.
> 
> What I would love to see is a proper entry into ./doc READMEs to
> clarify this issue (not necessarily with this patch series). It would
> help other users in the future.

Hm, if there are two protocol versions and the protocol is such a
braindead design that it doesn't send version in it's datagrams, then
instead of selecting one protocol version via Kconfig option at compile
time, we should add an optional arg for the fastboot command to select
which host you're talking to at run-time ?

-- 
Best regards,
Marek Vasut