[U-Boot] [patch 0/2] Some more USB-OHCI bugfixes

Markus Klotzbücher mk at denx.de
Wed Oct 8 12:12:00 CEST 2008


Hi Remy,

On Wed, Oct 08, 2008 at 10:54:13AM +0200, Remy Bohmer wrote:
> The USB OHCI init procedure sets the maximum message length the wrong way.
> A max of 64 bits should not be done by writing '64' in maxpacketsize, but '3'.
> While fixing this problem it turned out that there is more wrong here in this
> code it turned out that the wrong bits were checked to determine if the pipe
> was of type PIPE_INTERRUPT. This series fixes those errors also.

Ok, great!

> I made it 2 seperate patches. The 1st of this series is fully tested and correct
> on at least the AT91SAM9261 cores. I hope it fixes the known problems on
> AT91SAM9263 (and other) cores also, maybe Stelian can verify this.
> If it does not help on sam9263, it should not make it worse either...

Ok, looking forward to feedback...

> The 2nd patch, however, is created by search-for-the-same-errors-and-replace.
> I am not able to test that patch, I do not have the boards, so that needs to be
> done by others or by review. It is clear that code there is buggy in the
> first place.

Ok.

> These patches require my previous series called
> 'Improve stability USB memory sticks for the common OHCI USB layer.' to be
> applied before this series. So they should apply on the u-boot-usb git tree.
> --> git://git.denx.de/u-boot-usb.git

I'll test them here on sequoia and apply if they pass :-)

> I want to mention also, that everytime I look deeper into this code, I find new
> bugs. It appears that several parts of this code is written with interrupt
> handling in mind, while we have no interrupt handling at all.
> Assumptions are done that a interrupt handler does things asynchronous, causing
> long loops that have no real use at all...
> So, no guarantees that _all_ problems are solved by now...

Yes, this is ancient Linux code, but in contrast to the linux usb
stack wasn't rewritten several times. It was considered several times
to (re) import current Linux usb code, but it's obviously no small
job...

Thank you for the great work!

Best regards
Markus

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