From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
To: unlisted-recipients:; (no To-header on input)
Cc: Rodolfo Giometti <giometti@linux.it>,
Linux-MIPS <linux-mips@linux-mips.org>
Subject: Re: Porting Au1x000 USB host controller on u-boot
Date: Thu, 04 May 2006 21:16:19 +0400 [thread overview]
Message-ID: <445A36E3.4010809@ru.mvista.com> (raw)
In-Reply-To: <445A347A.5050507@ru.mvista.com>
Hello, I wrote:
>> I'm trying to implement support for USB host into u-boot. I
>> initialized the USB controller just as linux does, the EDs and the TDs
>> look like good in memory but the controller seems not well reading
>> them and on the bus I see random USB messages...
>> I think that there could be some problem on memory coherency... some
>> suggestion?
> try to disable USB controller's DMA coherency in the USB enable register
> (there's a related errata in all Au1xx0 family) -- the Linux driver
> doesn't do this though, and this shouldn't matter unless you're
> modifying USB buffers on the fly. :-)
AND make sure every buffer/TD/ED is written back / invalidated from cache
before the OHCI accesses them since the cache coherency on Au1xx0 is b0rken!
WBR, Sergei
WARNING: multiple messages have this Message-ID (diff)
From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Rodolfo Giometti <giometti@linux.it>,
Linux-MIPS <linux-mips@linux-mips.org>
Subject: Re: Porting Au1x000 USB host controller on u-boot
Date: Thu, 04 May 2006 21:16:19 +0400 [thread overview]
Message-ID: <445A36E3.4010809@ru.mvista.com> (raw)
Message-ID: <20060504171619.PwxiIpPkNOPMkbJQx5wFlNP8JXQrXs2VlJcrDp6HOkA@z> (raw)
In-Reply-To: <445A347A.5050507@ru.mvista.com>
Hello, I wrote:
>> I'm trying to implement support for USB host into u-boot. I
>> initialized the USB controller just as linux does, the EDs and the TDs
>> look like good in memory but the controller seems not well reading
>> them and on the bus I see random USB messages...
>> I think that there could be some problem on memory coherency... some
>> suggestion?
> try to disable USB controller's DMA coherency in the USB enable register
> (there's a related errata in all Au1xx0 family) -- the Linux driver
> doesn't do this though, and this shouldn't matter unless you're
> modifying USB buffers on the fly. :-)
AND make sure every buffer/TD/ED is written back / invalidated from cache
before the OHCI accesses them since the cache coherency on Au1xx0 is b0rken!
WBR, Sergei
next prev parent reply other threads:[~2006-05-04 17:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-05-04 9:53 Porting Au1x000 USB host controller on u-boot Rodolfo Giometti
2006-05-04 17:06 ` Sergei Shtylyov
2006-05-04 17:10 ` Sergei Shtylyov
2006-05-04 17:16 ` Sergei Shtylyov [this message]
2006-05-04 17:16 ` Sergei Shtylyov
2006-05-04 17:21 ` Rodolfo Giometti
2006-05-04 17:26 ` Sergei Shtylyov
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