From: Simon Ser <contact@emersion.fr>
To: Neil Armstrong <narmstrong@baylibre.com>
Cc: "daniel@ffwll.ch" <daniel@ffwll.ch>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
"mjourdan@baylibre.com" <mjourdan@baylibre.com>,
Kevin Hilman <khilman@baylibre.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-amlogic@lists.infradead.org"
<linux-amlogic@lists.infradead.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v4 7/8] drm/fourcc: amlogic: Add modifier definitions for the Scatter layout
Date: Wed, 25 Mar 2020 09:04:09 +0000 [thread overview]
Message-ID: <JgBZ7eZYMgXRNu_-E4ItS1bud9mEe15xptZEX_XhsM_h8_iIZTOmPokEVxPJYwX0wP0pmb5p-ymubyyZP3kVbcfuDNdmM0__L8wBR5IykfE=@emersion.fr> (raw)
In-Reply-To: <20200325085025.30631-8-narmstrong@baylibre.com>
On Wednesday, March 25, 2020 9:50 AM, Neil Armstrong <narmstrong@baylibre.com> wrote:
> Amlogic uses a proprietary lossless image compression protocol and format
> for their hardware video codec accelerators, either video decoders or
> video input encoders.
>
> This introduces the Scatter Memory layout, means the header contains IOMMU
> references to the compressed frames content to optimize memory access
> and layout.
>
> In this mode, only the header memory address is needed, thus the content
> memory organization is tied to the current producer execution and cannot
> be saved/dumped neither transferrable between Amlogic SoCs supporting this
> modifier.
I don't think this is suitable for modifiers. User-space relies on
being able to copy a buffer from one machine to another over the
network. It would be pretty annoying for user-space to have a blacklist
of modifiers that don't work this way.
Example of such user-space:
https://gitlab.freedesktop.org/mstoeckl/waypipe/
next prev parent reply other threads:[~2020-03-25 9:04 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-25 8:50 [PATCH v4 0/8] drm/meson: add support for Amlogic Video FBC Neil Armstrong
2020-03-25 8:50 ` [PATCH v4 1/8] drm/fourcc: Add modifier definitions for describing Amlogic Video Framebuffer Compression Neil Armstrong
2020-03-25 8:50 ` [PATCH v4 2/8] drm/meson: add Amlogic Video FBC registers Neil Armstrong
2020-03-25 8:50 ` [PATCH v4 3/8] drm/meson: overlay: setup overlay for Amlogic FBC Neil Armstrong
2020-03-25 8:50 ` [PATCH v4 4/8] drm/meson: crtc: handle commit of Amlogic FBC frames Neil Armstrong
2020-03-25 8:50 ` [PATCH v4 5/8] drm/fourcc: amlogic: Add modifier definitions for Memory Saving option Neil Armstrong
2020-03-25 8:50 ` [PATCH v4 6/8] drm/meson: overlay: setup overlay for Amlogic FBC Memory Saving mode Neil Armstrong
2020-03-25 8:50 ` [PATCH v4 7/8] drm/fourcc: amlogic: Add modifier definitions for the Scatter layout Neil Armstrong
2020-03-25 9:04 ` Simon Ser [this message]
2020-03-25 10:24 ` Neil Armstrong
2020-03-25 13:49 ` Pekka Paalanen
2020-03-25 16:18 ` Neil Armstrong
2020-03-26 9:36 ` Pekka Paalanen
2020-03-27 14:14 ` Neil Armstrong
2020-03-30 14:41 ` Pekka Paalanen
2020-03-25 8:50 ` [PATCH v4 8/8] drm/meson: overlay: setup overlay for Amlogic FBC Scatter Memory layout Neil Armstrong
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='JgBZ7eZYMgXRNu_-E4ItS1bud9mEe15xptZEX_XhsM_h8_iIZTOmPokEVxPJYwX0wP0pmb5p-ymubyyZP3kVbcfuDNdmM0__L8wBR5IykfE=@emersion.fr' \
--to=contact@emersion.fr \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=khilman@baylibre.com \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mjourdan@baylibre.com \
--cc=narmstrong@baylibre.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).