From: Rui Salvaterra <rsalvaterra@gmail.com>
To: benh@kernel.crashing.org
Cc: hch@lst.de, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
Subject: Re: use generic DMA mapping code in powerpc V4
Date: Tue, 11 Dec 2018 09:37:02 +0000 [thread overview]
Message-ID: <CALjTZvZ1Ud4P_XqB23Yq=815VyF=UbbT8YCFjTaPN=5tORWrtQ@mail.gmail.com> (raw)
In-Reply-To: <8a2e104a6c5b745adca8e7f3310af564f3b8a75d.camel@kernel.crashing.org>
On Mon, 10 Dec 2018 at 20:49, Benjamin Herrenschmidt
<benh@kernel.crashing.org> wrote:
>
[snip]
>
> AGP is a gigantic nightmare :-) It's not just cache coherency issues
> (some implementations are coherent, some aren't, Apple's is ... weird).
>
> Apple has all sort of bugs, and Darwin source code only sheds light on
> some of them. Some implementation can only read, not write I think, for
> example. There are issues with transfers crossing some boundaries I
> beleive, but it's all unclear.
>
> Apple makes this work with a combination of hacks in the AGP "driver"
> and the closed source GPU driver, which we don't see.
>
> I have given up trying to make that stuff work reliably a decade ago :)
>
> Cheers,
> Ben.
That's what I was afraid of… what a mess. At least now I have a
definitive answer from one of the original authors of the code, thanks
a lot, Ben. :)
I have an unresearched belief that AGP support was hacked in the Mac
series as an afterthought (weren't they supposed to be PCI/PCI-X
only?), and your explanation surely seems to corroborate. :/
next prev parent reply other threads:[~2018-12-11 9:37 UTC|newest]
Thread overview: 125+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-29 19:45 use generic DMA mapping code in powerpc V4 Rui Salvaterra
2018-11-30 10:32 ` Christoph Hellwig
2018-11-30 11:44 ` Rui Salvaterra
2018-11-30 16:41 ` Rui Salvaterra
2018-12-02 6:11 ` Benjamin Herrenschmidt
2018-12-08 17:17 ` Christoph Hellwig
2018-12-10 17:04 ` Rui Salvaterra
2018-12-10 19:33 ` Christoph Hellwig
2018-12-10 20:03 ` Rui Salvaterra
2018-12-10 20:49 ` Benjamin Herrenschmidt
2018-12-11 9:37 ` Rui Salvaterra [this message]
-- strict thread matches above, loose matches on Subject: below --
2018-11-14 8:22 Christoph Hellwig
2018-11-27 7:42 ` Christoph Hellwig
2018-11-27 22:05 ` Benjamin Herrenschmidt
2018-11-28 11:05 ` Michael Ellerman
2018-11-28 15:55 ` Christian Zigotzky
2018-11-28 20:02 ` Christian Zigotzky
2018-11-28 20:35 ` Michal Suchánek
2018-11-29 17:03 ` Christoph Hellwig
2019-12-19 13:54 ` Christian Zigotzky
2018-11-29 12:05 ` Christian Zigotzky
2018-11-29 15:30 ` Christian Zigotzky
2018-11-29 17:03 ` Christoph Hellwig
2018-11-29 23:07 ` Christian Zigotzky
2018-11-30 10:53 ` Christoph Hellwig
2018-11-30 12:23 ` Christian Zigotzky
2018-11-30 13:10 ` Christoph Hellwig
2018-11-30 15:29 ` Christian Zigotzky
2018-12-04 7:31 ` Christian Zigotzky
2018-12-04 9:53 ` Christian Zigotzky
2018-12-04 14:24 ` Christoph Hellwig
2018-12-05 9:44 ` Christian Zigotzky
2018-12-05 14:05 ` Christoph Hellwig
2018-12-06 10:55 ` Christian Zigotzky
2018-12-06 17:10 ` Christian Zigotzky
2018-12-06 19:36 ` Christoph Hellwig
2018-12-07 7:48 ` Christian Zigotzky
2018-12-07 13:45 ` Christian Zigotzky
2018-12-07 18:33 ` Christian Zigotzky
2018-12-08 10:29 ` Christian Zigotzky
2018-12-08 13:47 ` Christian Zigotzky
2018-12-09 14:20 ` Christian Zigotzky
2018-12-09 18:26 ` Christian Zigotzky
2018-12-10 15:54 ` Christian Zigotzky
2018-12-11 14:28 ` Christian Zigotzky
2018-12-11 18:17 ` Christian Zigotzky
2018-12-12 0:47 ` Benjamin Herrenschmidt
2018-12-12 7:03 ` Christian Zigotzky
2018-12-12 14:15 ` Christoph Hellwig
2018-12-12 14:39 ` Christian Zigotzky
2018-12-13 8:41 ` Christian Zigotzky
2018-12-13 9:10 ` Christoph Hellwig
2018-12-13 9:47 ` Christian Zigotzky
2018-12-13 11:19 ` Christian Zigotzky
2018-12-13 11:25 ` Christoph Hellwig
2018-12-13 13:34 ` Christian Zigotzky
2018-12-13 17:48 ` Christian Zigotzky
2018-12-13 21:53 ` Christian Zigotzky
2018-12-14 12:00 ` Christian Zigotzky
2018-12-14 16:45 ` Christoph Hellwig
2019-01-03 7:36 ` Christoph Hellwig
2019-01-03 19:26 ` Christian Zigotzky
2019-01-05 16:03 ` Christian Zigotzky
2019-01-09 9:31 ` Christian Zigotzky
2019-01-11 2:10 ` Christian Zigotzky
2019-01-12 18:14 ` Christian Zigotzky
2019-01-15 8:07 ` Christian Zigotzky
2019-01-15 8:49 ` Christian Zigotzky
2019-01-15 10:55 ` Christian Zigotzky
2019-01-15 13:35 ` Christoph Hellwig
2019-01-15 13:56 ` Christian Zigotzky
2019-01-15 15:17 ` Christoph Hellwig
2019-01-17 9:21 ` Christian Zigotzky
2019-01-17 9:31 ` Christoph Hellwig
2019-01-17 9:44 ` Christian Zigotzky
2019-01-18 8:35 ` Christoph Hellwig
2019-01-18 11:10 ` Christian Zigotzky
2019-01-18 11:28 ` Christoph Hellwig
2019-01-18 12:07 ` Christian Zigotzky
2019-01-18 12:18 ` Christoph Hellwig
2019-01-18 12:46 ` Christian Zigotzky
2019-01-18 12:55 ` Christoph Hellwig
2019-01-18 15:06 ` Christian Zigotzky
2019-01-19 11:40 ` Christian Zigotzky
2019-01-19 11:52 ` Christian Zigotzky
2019-01-19 13:02 ` Christoph Hellwig
2019-01-19 14:04 ` Christoph Hellwig
2019-01-21 14:38 ` Christian Zigotzky
2019-01-23 14:34 ` Christian Zigotzky
2019-01-25 13:37 ` Christian Zigotzky
2019-01-27 13:13 ` Christian Zigotzky
2019-01-28 7:04 ` Christoph Hellwig
2019-01-28 16:22 ` Christoph Hellwig
2019-01-28 16:52 ` Christian Zigotzky
2019-01-29 15:03 ` Christian Zigotzky
2019-01-29 16:14 ` Christoph Hellwig
2019-01-29 16:34 ` Christoph Hellwig
2019-01-30 4:40 ` Christian Zigotzky
2019-01-31 12:48 ` Christian Zigotzky
2019-02-01 8:04 ` Christoph Hellwig
2019-02-01 16:54 ` Christian Zigotzky
2019-02-03 16:49 ` Christian Zigotzky
2019-02-04 7:56 ` Christoph Hellwig
2019-02-04 12:13 ` Christian Zigotzky
2019-02-04 12:38 ` Christoph Hellwig
2019-02-06 13:45 ` Christian Zigotzky
2019-02-06 15:15 ` Christoph Hellwig
2019-02-06 15:16 ` Christoph Hellwig
2019-02-07 4:34 ` Christian Zigotzky
2019-02-08 9:01 ` Christian Zigotzky
2019-02-08 9:18 ` Christoph Hellwig
2019-02-08 10:59 ` Christian Zigotzky
2019-02-10 12:00 ` Christian Zigotzky
[not found] ` <0042290A-2939-4EBA-A638-D404FA2055ED@xenosoft.de>
2019-02-11 7:21 ` Christian Zigotzky
2019-02-11 7:38 ` Christoph Hellwig
2019-02-12 12:42 ` Christian Zigotzky
2019-02-12 15:25 ` Christoph Hellwig
2019-02-12 19:31 ` Christian Zigotzky
2019-02-12 19:50 ` Christian Zigotzky
2019-02-12 19:52 ` Christoph Hellwig
2018-11-29 17:02 ` Christoph Hellwig
2018-11-30 3:17 ` Benjamin Herrenschmidt
2018-12-08 17:03 ` Christoph Hellwig
2018-12-16 16:51 ` Christoph Hellwig
2018-12-17 1:14 ` Michael Ellerman
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