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Date:   Tue, 22 Jun 2021 08:04:53 +0000
To:     Tomohito Esaki <etom@igel.co.jp>
From:   Simon Ser <contact@emersion.fr>
Cc:     Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-renesas-soc@vger.kernel.org
Reply-To: Simon Ser <contact@emersion.fr>
Subject: Re: [PATH 0/4] [RFC] Support virtual DRM
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In-Reply-To: <20210621064403.26663-1-etom@igel.co.jp>
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On Monday, June 21st, 2021 at 08:43, Tomohito Esaki <etom@igel.co.jp> wrote=
:

> Virtual DRM splits the overlay planes of a display controller into multip=
le
> virtual devices to allow each plane to be accessed by each process.
> This makes it possible to overlay images output from multiple processes o=
n a
> display. For example, one process displays the camera image without compo=
sitor
> while another process overlays the UI.

Updating the KMS state from multiple processes doesn't sound like a
good idea. This opens up synchronization and global device limits
issues.

Are you aware of DRM leasing?