[U-Boot-Users] reg ISP 1561 integration with u-boot1.1.6

Markus Klotzbücher mk at denx.de
Thu Jan 11 15:11:08 CET 2007

Hi Matthias,

Matthias Fuchs <matthias.fuchs at esd-electronics.com> writes:

> On Thursday 11 January 2007 11:17, Markus Klotzbücher wrote:
>> Hi Matthias,
>> Matthias Fuchs <matthias.fuchs at esd-electronics.com> writes:
>> > On Wednesday 10 January 2007 23:01, Markus Klotzbücher wrote:
>> >> Matthias Fuchs <matthias.fuchs at esd-electronics.com> writes:
>> >> > The main changes concern endianess fixes. The former code only supports OHCI 
>> >> > controller with the same endianess as the CPU. The other fix allows a offset 
>> >> 
>> >> IIRC same problem with the 440EP and MPC5200, thats what the extra
>> >> #ifdef in drivers/usb_ohci.c:103 is for.
>> > These are different issues! usb_ohci.c uses readl and writel to access the 
>> > controller's registers from the CPU (e.g. ohci.regs). The original code never
>> > swaps here. But a PCI OHCI controller on a PowerPC needs it. The mXX_swap 
>> > macros are used to swap data fields in structures that are passed to the host 
>> > controller indirectly.
>> I get it. So in the end we have four cases: byte swapping register
>> access or not _and_ byte swapping data or not. Right? Doesn't sound too
>> complicated.
> What about taking some code / macros from the linux kernel (usb/host/ohci.h)?
> It seems that all we need is the CONFIG_USB_OHCI_BIG_ENDIAN define.

Seems reasonable. So we'll use these for register accesses, and the rest
stays as is doing CPU dependant byteswapping based on the LITTLEENDIAN
define (include/usb.h). Ok?

>> >> > 2) I had to disable the 'return -1' statement for an unfinished urb in 
>> >> > sohci_submit_job(). Why isn't it finished?
>> >> 
>> >> I really don't know, I guess only you can answer this!
>> > This answer helps me a lot. Why is the urb_finished stuff needed? I go better
>> > without :-)
>> Did you see the comment in usb_ohci.c:1355? It's to make sure a
>> transaction has completed before a new one is started. I'm not insisting
>> to keep this if it's useless, but we need to prove that first. Obviously
>> it was put there for some reason.
> The code makes sense. But it does not work for me. I will investigate some more time 
> on this and figure it out.



Markus Klotzbuecher

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