From: Rob Herring <robh+dt@kernel.org>
To: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
Arnd Bergmann <arnd@arndb.de>,
Robin Murphy <robin.murphy@arm.com>,
dri-devel <dri-devel@lists.freedesktop.org>,
Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
Chen-Yu Tsai <wens@csie.org>, Yong Deng <yong.deng@magewell.com>,
Frank Rowand <frowand.list@gmail.com>,
Dave Martin <dave.martin@arm.com>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 0/7] sunxi: Add DT representation for the MBUS controller
Date: Tue, 3 Apr 2018 11:03:30 -0500 [thread overview]
Message-ID: <CAL_Jsq+cURC780ivftY1v3P59g5UKAHwb48raXXB6huQ2KBvuQ@mail.gmail.com> (raw)
In-Reply-To: <cover.54a07919b9d7fe8d7c90e9f4929648013e641cff.1522761929.git-series.maxime.ripard@bootlin.com>
On Tue, Apr 3, 2018 at 8:29 AM, Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> Hi,
>
> We've had for quite some time to hack around in our drivers to take into
> account the fact that our DMA accesses are not done through the parent
> node, but through another bus with a different mapping than the CPU for the
> RAM (0 instead of 0x40000000 for most SoCs).
>
> After some discussion after the submission of a camera device suffering of
> the same hacks, I've decided to put together a serie that introduce a
> property called dma-parent that allows to express the DMA relationship
> between a master and its bus, even if they are not direct parents in the DT.
Reading thru v6 of the camera driver, it seems like having
intermediate buses would solve the problem in your case?
As Arnd mentioned in that thread, something new needs to address all
the deficiencies with dma-ranges and describing DMA bus topologies.
This doesn't address the needs of describing bus interconnects.
There's been some efforts by the QCom folks with an interconnect
binding. They've mostly punted (for now at least) to not describing
the whole interconnect in DT and keeping the details in a driver.
On the flip side, this does mirror the established pattern used by
interrupts, so maybe it's okay on it's own. I'll wait for others to
comment.
Rob
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2018-04-03 16:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-03 13:29 [PATCH 0/7] sunxi: Add DT representation for the MBUS controller Maxime Ripard
2018-04-03 13:29 ` [PATCH 1/7] dt-bindings: Add a dma-parent property Maxime Ripard
2018-04-03 13:29 ` [PATCH 2/7] dt-bindings: bus: Add binding for the Allwinner MBUS controller Maxime Ripard
2018-04-03 13:29 ` [PATCH 3/7] of: address: Add parent pointer to the __of_translate_address args Maxime Ripard
2018-04-03 13:29 ` [PATCH 4/7] of: address: Add support for the dma-parent property Maxime Ripard
2018-04-03 13:29 ` [PATCH 5/7] drm/sun4i: Rely on dma-parent for our RAM offset Maxime Ripard
2018-04-03 14:56 ` Daniel Vetter
2018-04-03 13:29 ` [PATCH 6/7] clk: sunxi-ng: sun5i: Export the MBUS clock Maxime Ripard
2018-04-09 21:23 ` Rob Herring
2018-04-03 13:29 ` [PATCH 7/7] ARM: dts: sun5i: Add the MBUS controller Maxime Ripard
2018-04-03 16:03 ` Rob Herring [this message]
2018-04-09 9:22 ` [PATCH 0/7] sunxi: Add DT representation for " Maxime Ripard
2018-05-31 12:52 ` Maxime Ripard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAL_Jsq+cURC780ivftY1v3P59g5UKAHwb48raXXB6huQ2KBvuQ@mail.gmail.com \
--to=robh+dt@kernel.org \
--cc=arnd@arndb.de \
--cc=dave.martin@arm.com \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=frowand.list@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=maxime.ripard@bootlin.com \
--cc=paul.kocialkowski@bootlin.com \
--cc=robin.murphy@arm.com \
--cc=thomas.petazzoni@bootlin.com \
--cc=wens@csie.org \
--cc=yong.deng@magewell.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).