From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "dibacco@libero.it" <dibacco@libero.it>
Cc: linuxppc-dev <linuxppc-dev@ozlabs.org>
Subject: Re: __pa giving strange phys address on PPC
Date: Thu, 08 Jan 2009 09:27:59 +1100 [thread overview]
Message-ID: <1231367279.2142.25.camel@pasglop> (raw)
In-Reply-To: <KD4CZC$63E26AC2C9F30D8D9F146E56F7574045@libero.it>
On Wed, 2009-01-07 at 21:59 +0100, dibacco@libero.it wrote:
> Hi all,
>
> I'm using a linux 2.6.19 (from Denx ELDK) on a PPC MPC880. In a driver
> (that uses TDM channels) I have some calls to __pa to get the physical
> address corresponding to a virtual address. The physical address
> returned by __pa is higher than the maximum physical memory I have on
> the board. This result make my driver hang. The driver I'm trying to
> use was written for a 2.4 kernel and I'm wondering if I have to
> replace the calls to __pa with some other API/MACRO.
__pa can only be used on memory coming from the kernel linear mapping.
You probably need to change your driver to use the proper DMA mapping
APIs instead
Cheers,
Ben.
next prev parent reply other threads:[~2009-01-07 22:28 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-07 20:59 __pa giving strange phys address on PPC dibacco
2009-01-07 22:27 ` Benjamin Herrenschmidt [this message]
2009-01-08 21:03 ` Josh Boyer
-- strict thread matches above, loose matches on Subject: below --
2009-01-07 21:11 dibacco
2009-01-08 0:25 ` Benjamin Herrenschmidt
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