isochronous mode of USB audio device on MPC5200

[Benny Liu]

Hi Sylvain,

    You are right.

    I am using the lasted kernel source from Denx web site, kernel version is 2.4.25, but the td definition in usb-ohci.h is still wrong. I modified the hwPSW definition, now the isochronous mode is ok.

    Thank you very much.

Best Regards,
Benny


----- Original Message ----- 
From: "Sylvain Munaut" <tnt at 246tNt.com>
To: "Benny Liu" <benny at cellvision.com.cn>
Cc: <linuxppc-dev at ozlabs.org>
Sent: Sunday, January 02, 2005 6:19 AM
Subject: Re: isochronous mode of USB audio device on MPC5200


> Hi Benny
> 
> 
> What version of the kernel ?
> 
> 
> In the last 2.4 I built ( quite a while ago ... ) there was a flaw
> in the handling of the hwPSW field in the OHCI driver when on big-endian
> platform. Since this field is only used fot Isochronous the problem
> didn't show up before.
> 
> The fields were assume by the kernel to be in this order
> 
> hwPSW[0]
> hwPSW[1]
> hwPSW[2]
> hwPSW[3]
> ...
> 
> But in fact since the figure in ohci spec shows this array not as an
> array of 16bits fields but as an array of 32bits integer, each containing
> two hwPSW[] in little endian order, they ended up implemented in the order
> 
> hwPSW[1]
> hwPSW[0]
> hwPSW[3]
> hwPSW[2]
> ...
> 
> (fscked up isn't it ? ;)
> 
> 
> And that was not taken into account ...
> 
> 
> I notified W.Denk about the problem a while ago, don't know if any
> action has been taken.
> 
> 
> 
> 
> Sylvain Munaut
> 
> 
> Benny Liu wrote:
> 
>> Hi, everyone, happy new year!
>> Did anyone try usb audio device or other isochronous mode usb devices
>> on Icecube board(Motorola MPC5200)?
>> I tried, but it reports the following message:
>> /"host/usb-ohci.c: OHCI Unrecoverable Error, controller usb-0 disabled"/
>> After this message, the host controller is disabled.
>> Thanks a lot.
>>
>>------------------------------------------------------------------------
>>
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> 
>