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Date:      Tue, 7 Jul 2009 18:46:39 +0200
From:      Hans Petter Selasky <hselasky@c2i.net>
To:        Piotr =?iso-8859-2?q?Zi=EAcik?= <kosmo@semihalf.com>
Cc:        freebsd-arm@freebsd.org, thompsa@freebsd.org, freebsd-usb@freebsd.org
Subject:   Re: CPU Cache and busdma usage in USB
Message-ID:  <200907071846.42086.hselasky@c2i.net>
In-Reply-To: <200907071550.28781.kosmo@semihalf.com>
References:  <200906231035.43096.kosmo@semihalf.com> <200907051236.22783.hselasky@c2i.net> <200907071550.28781.kosmo@semihalf.com>

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On Tuesday 07 July 2009 15:50:28 Piotr Zi=EAcik wrote:
> > I did not find time yet to test on my AT91RM9200 board. I hope to do a
> > test this week. Did you at semihalf find anything?
>

Hi,

> I had Checked USB behaviour on PowerPC without hardware cache coherency.
> The problem also exists here and patch helps.

In my source code view the busdma sync function is empty for power-pc. Your=
=20
patch should have no effect at all for sync operations?

>
> I also generated some logs which you asked for:

Thanks. I will try to make a build for AT91RM9200 tonight.

Did you test my suggested patch:

> Try adding:
>
>                 cpu_dcache_wb_range((vm_offset_t)buf, len);
>                 cpu_l2cache_wb_range((vm_offset_t)buf, len);
>
> Before:
>
>                         cpu_dcache_wbinv_range((vm_offset_t)buf, len);
>                         cpu_l2cache_wbinv_range((vm_offset_t)buf, len);
>
> In: sys/arm/arm/busdma_machdep.c

Or have you got any comments on that?

=2D-HPS




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