[U-Boot] Debugging, Why USB is not stable

[Remy Bohmer]

Hi Detlev,

2010/8/30 Detlev Zundel <dzu at denx.de>:
> Hi Gérald,
>
>> I have some few problems with usb start / reset commands on last uboot.
>>
>> USB hard drive are not always detected.
>>
>> Is there something I missed ?
>
> Only the fact that USB is a nightmare to work with.  No, honestly, we
> have a continuous stream of USB related problems with the current USB
> code.

This is not what I notice on the amount of fixes that are posted on the list...
The only fixes I have seen the last year or two were related to newly
added host-controller support. Apart from that it is quite silent in
the u-boot-usb tree...
But, anyway. I know it has some stability issues, although it is now
much better compared to a year ago...

> As I understand it this results from the ever more diverging USB
> implementation in U-Boot and e.g. in the Linux kernel.

Indeed, It has diverged that much that I did not succeed in finding
the real origin of the code...

> Sometimes I get the impression that we would save a lot of headache by
> starting afresh and porting the current Linux code into U-Boot thus
> leverage all this, but nobody yet dared to start such a feat.

Hey... I have dared to start it!
(But it is a real pain to do it properly, and I stopped half way due
to lack of time...)

Kind regards,

Remy