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Date: Tue, 29 Apr 2003 16:23:22 +0400
From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
To: Marc Zyngier <mzyngier@freesurf.fr>
Cc: rth@twiddle.net, linux-kernel@vger.kernel.org
Subject: Re: [Patch] DMA mapping API for Alpha
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References: <wrp65oycvrw.fsf@hina.wild-wind.fr.eu.org> <20030429150532.A3984@jurassic.park.msu.ru> <wrpvfwx5xcq.fsf@hina.wild-wind.fr.eu.org>
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In-Reply-To: <wrpvfwx5xcq.fsf@hina.wild-wind.fr.eu.org>; from mzyngier@freesurf.fr on Tue, Apr 29, 2003 at 01:58:29PM +0200
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On Tue, Apr 29, 2003 at 01:58:29PM +0200, Marc Zyngier wrote:
> That's exactly what I wanted to avoid : It we feed NULL (for a non PCI
> device) to pci_map_single (for example), we limit the max DMA address
> to 24 bits, and this is quite bad for an EISA device, which is 32 bits
> capable.

Agreed, but what if your EISA-PCI bridge has only 30 address lines wired
to PCI? Yes, we can check this for EISA device because it has *real*
PCI parent (thanks, Marc :-), but what about ISA/legacy/whatever drivers?
I doubt that all of them bother to set dma_mask pointer (so you can have
an oops there).

Ivan.