From: Andi Kleen <ak@muc.de>
To: Arjan van de Ven <arjanv@redhat.com>
Cc: linux-scsi@vger.kernel.org, gibbs@scsiguy.com
Subject: Re: aic7xxx strange code
Date: Thu, 01 Jan 2004 23:31:17 +0100 [thread overview]
Message-ID: <m3vfnvi9my.fsf@averell.firstfloor.org> (raw)
In-Reply-To: <20040101162823.GC18742@devserv.devel.redhat.com> (Arjan van de Ven's message of "Thu, 1 Jan 2004 17:28:23 +0100")
Arjan van de Ven <arjanv@redhat.com> writes:
>
> This is the first time I've seen this bug (thanks again for reporting it)
> and it's clearly an API violation of the ONE API in linux which is very well
> documented so no other platform will have copied this bad bug... Adaptect
It may be well documented, but ports do not follow the documentation
very well in that area. In particular i386 handles the consistent dma mask
completely different than all the 64bit ports. Small overview:
Architecture pci_alloc_consistent uses
i386 normal dma mask
most 64bit archs/old x86-64 hardcoded 0xffffffff
newer IA64/some x86-64 consistent dma mask (2)
newest x86-64 normal dma mask & consistent dma mask (1) (2)
old redhat IA64 hardcoded 0xffffffffffffffff (?)
(1) to be bug-to-bug compatible with i386, some drivers rely on that.
(2) consistent dma mask is normally equivalent to hardcoded 0xffffffff
because that is the default value
It's quite a mess unfortunately. Due to (2) the 64bit architectures
are consistent, except for that old IA64. But i386 doing something
different is quite a problem.
-Andi
next prev parent reply other threads:[~2004-01-01 22:31 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-12-31 15:46 aic7xxx strange code Arjan van de Ven
2003-12-31 18:36 ` Justin T. Gibbs
2004-01-01 10:08 ` Arjan van de Ven
2004-01-01 16:16 ` Justin T. Gibbs
2004-01-01 16:17 ` Arjan van de Ven
2004-01-01 16:21 ` Justin T. Gibbs
2004-01-01 16:28 ` Arjan van de Ven
2004-01-01 22:31 ` Andi Kleen [this message]
2004-01-01 22:34 ` Arjan van de Ven
2004-01-01 23:14 ` Andi Kleen
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