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From: Johannes Erdfelt <johannes@erdfelt.com>
To: linux-kernel@vger.kernel.org
Subject: Re: struct page to 36 (or 64) bit bus address?
Date: Fri, 10 Aug 2001 03:56:56 -0400	[thread overview]
Message-ID: <20010810035654.W3126@sventech.com> (raw)
In-Reply-To: <20010809151022.C1575@sventech.com> <E15UvLO-0007tH-00@the-village.bc.nu> <15218.61869.424038.30544@pizda.ninka.net> <20010809163531.D1575@sventech.com> <slrn9n71kn.28q.kraxel@bytesex.org>
In-Reply-To: <slrn9n71kn.28q.kraxel@bytesex.org>; from kraxel@bytesex.org on Fri, Aug 10, 2001 at 07:00:39AM +0000

On Fri, Aug 10, 2001, Gerd Knorr <kraxel@bytesex.org> wrote:
> > > Note, if you use the "bttv method" (ie. virt_to_bus) your driver will
> > > then fail to compile on several platforms.
> >  
> >  So noted. I already have a PCI DMA API version, but I wanted to code up
> >  a "i have an i386 and gigs of memory" version as well.
> 
> Forgot about virt_to_bus() then, it doesn't work for highmem.

I knew that already :)

The thing about 64 bit PCI cards is that there is no such thing as
highmem, so we don't need to worry about mapping it and using bounce
buffers. The device just DMA's. That's why I originally asked.

I took a look at the code in the 2.4.7 version of bttv.c and it wasn't
readily obvious what Alan was referring to. I'll spend some more time
tomorrow looking into it.

JE


  reply	other threads:[~2001-08-10  7:57 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-08-09 18:40 struct page to 36 (or 64) bit bus address? Johannes Erdfelt
2001-08-09 19:09 ` Alan Cox
2001-08-09 19:10   ` Johannes Erdfelt
2001-08-09 19:19     ` Alan Cox
2001-08-09 20:25     ` David S. Miller
2001-08-09 20:35       ` Johannes Erdfelt
2001-08-10  7:00         ` Gerd Knorr
2001-08-10  7:56           ` Johannes Erdfelt [this message]
2001-08-10 21:58         ` David S. Miller
2001-08-11  7:09           ` Gerd Knorr
2001-08-12 10:49             ` Write Combining (Write Coalescing) on memory mapped I/O on IA64 Steffen Persvold
2001-08-11 15:32           ` struct page to 36 (or 64) bit bus address? Jens Axboe
2001-08-11 15:56         ` Andrea Arcangeli
2001-08-11 16:13           ` Sandy Harris
2001-08-12  8:00           ` David S. Miller
     [not found] <no.id>
2001-08-12 11:49 ` Alan Cox
2001-08-13 13:51 ` David S. Miller
2001-08-13 14:09 ` Alan Cox
2001-08-13 14:21 ` David S. Miller
2001-08-13 19:07   ` Gérard Roudier
2001-08-13 19:42   ` David S. Miller
2001-08-13 15:10 ` Alan Cox

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