Linux-ARM-Kernel Archive on
 help / color / Atom feed
From: Marek Szyprowski <>
To: "Christoph Hellwig" <>,
	"Pawel Osciak" <>,
	"Kyungmin Park" <>,
	"Niklas Söderlund" <>
Cc: Russell King <>,,,
	Mauro Carvalho Chehab <>,,,
Subject: Re: fix a layering violation in videobuf2 and improve dma_map_resource v2
Date: Fri, 1 Feb 2019 08:05:21 +0100
Message-ID: <> (raw)
In-Reply-To: <>

Hi All,

On 2019-01-18 12:37, Christoph Hellwig wrote:
> Hi all,
> this series fixes a rather gross layering violation in videobuf2, which
> pokes into arm DMA mapping internals to get a DMA address for memory that
> does not have a page structure, and to do so fixes up the dma_map_resource
> implementation to not provide a somewhat dangerous default and improve
> the error handling.
> Changes since v1:
>  - don't apply bus offsets in dma_direct_map_resource

Works fine on older Exynos based boards with IOMMU and CMA disabled.

Tested-by: Marek Szyprowski <>

Best regards
Marek Szyprowski, PhD
Samsung R&D Institute Poland

linux-arm-kernel mailing list

  parent reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <>
2019-01-18 11:37 ` Christoph Hellwig
2019-01-18 11:37   ` [PATCH 1/3] dma-mapping: remove the default map_resource implementation Christoph Hellwig
2019-01-18 11:37   ` [PATCH 2/3] dma-mapping: don't BUG when calling dma_map_resource on RAM Christoph Hellwig
2019-01-18 11:37   ` [PATCH 3/3] videobuf2: replace a layering violation with dma_map_resource Christoph Hellwig
2019-02-01  7:05   ` Marek Szyprowski [this message]
2019-02-01  9:07     ` fix a layering violation in videobuf2 and improve dma_map_resource v2 Christoph Hellwig

Reply instructions:

You may reply publically 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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on

Archives are clonable:
	git clone --mirror linux-arm-kernel/git/0.git
	git clone --mirror linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ \
	public-inbox-index linux-arm-kernel

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone