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From: Niklaus Giger <niklaus.giger@member.fsf.org>
To: "- Reyneke" <reynekejunk@hotmail.com>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: Howto use PPC4xx memory to memory DMA
Date: Fri, 19 Jan 2007 21:47:27 +0100	[thread overview]
Message-ID: <200701192147.27340.niklaus.giger@member.fsf.org> (raw)
In-Reply-To: <BAY7-F81C4E9CDFE4D0599271E7BEA90@phx.gbl>

Am Freitag, 19. Januar 2007 10:35 schrieb - Reyneke:
> Ooh - and the 3d thing - cache coherence. I.e.:
>
> 	dma_cache_inv((u32)mem, (u32)nBytes);
>
> >>Here are a few things to check:
Thanks a lot for your tips. First I called
a) __get_free_pages(GFP_KERNEL | GFP_DMA, get_order(size));
for the source and destination address.
Then before calling ppc4xx_enable_dma I added
b) ppc4xx_set_src_addr(DMA_NR, virt_to_bus(src));
c) ppc4xx_set_src_addr(DMA_NR, virt_to_bus(dst));
d) flush_dcache_all(); 
With these changes I got at least one byte copied. After fixing the 
ppc4xx_enable_dma everything worked fine. (Patch posted a few minutes ago.)

Did you manage to use DMA on PLB peripheral bus on a memory mapped dev? I 
think there one should also increment the source or destination address. But 
I have no example HW/code at hand to test these two cases too.

Best regards
-- 
Niklaus Giger

  reply	other threads:[~2007-01-19 20:47 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-19  9:35 Howto use PPC4xx memory to memory DMA - Reyneke
2007-01-19 20:47 ` Niklaus Giger [this message]
  -- strict thread matches above, loose matches on Subject: below --
2008-01-07 10:57 padmanabha
2007-01-19 22:32 Alexis Berlemont
2007-01-21 19:47 ` Eugene Surovegin
2007-01-19  8:49 - Reyneke
2007-01-19 19:48 ` T Ziomek
2007-01-21 21:28   ` - Reyneke
2007-01-22 17:18     ` Eugene Surovegin
2007-01-18 22:16 Niklaus Giger

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