From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Andrzej Hajda <a.hajda@samsung.com>
Cc: Lubomir Rintel <lkundrak@v3.sk>,
DRI Development <dri-devel@lists.freedesktop.org>,
Liviu Dudau <Liviu.Dudau@arm.com>, Peter Rosin <peda@axentia.se>
Subject: Re: Armada DRM: bridge with componentized devices
Date: Tue, 8 Jan 2019 11:38:55 +0000 [thread overview]
Message-ID: <20190108113855.GS11171@n2100.armlinux.org.uk> (raw)
In-Reply-To: <899be5e6-673d-b6c2-94d9-3b4ed3acda20@samsung.com>
On Tue, Jan 08, 2019 at 12:25:34PM +0100, Andrzej Hajda wrote:
> Issues with device links have nothing to do with hotplugging, they are
> generic - lifetime of the objects (drm_bridge, drm_panel) is just
> slightly different of lifetime of device links, and this is racy even if
> you do not want hotplugging. Moreover since drm_dev is not device (has
> no associated struct device) assuming we can reuse its parent to create
> device link results in circular dependencies.
How about having the device links created depending on whether the
main drm driver wants them or not - that would mean that Exynos
could continue avoiding them, but others that want them can have
the links?
I don't think the links should be created when the bridge is attached,
they should be created when the main drm driver gains its first
reference to the drm_bridge (via of_drm_find_bridge()) - since that's
the point where things may explode if the drm_bridge goes away.
Calling drm_bridge_attach() for a bridge that has been unbound will
be a use-after-free bug, so using device links at that point is way
too late.
--
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next prev parent reply other threads:[~2019-01-08 11:39 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-03 9:47 Armada DRM: bridge with componentized devices Lubomir Rintel
2019-01-03 13:11 ` Russell King - ARM Linux
2019-01-07 10:45 ` Daniel Vetter
2019-01-07 11:26 ` Andrzej Hajda
2019-01-07 16:08 ` Daniel Vetter
2019-01-07 16:27 ` Andrzej Hajda
2019-01-07 21:56 ` Daniel Vetter
2019-01-08 8:35 ` Andrzej Hajda
2019-01-08 8:47 ` Daniel Vetter
2019-01-08 9:22 ` Andrzej Hajda
2019-01-08 10:23 ` Russell King - ARM Linux
2019-01-08 10:32 ` Andrzej Hajda
2019-01-08 10:24 ` Daniel Vetter
2019-01-08 11:25 ` Andrzej Hajda
2019-01-08 11:38 ` Russell King - ARM Linux [this message]
2019-01-08 12:27 ` Andrzej Hajda
2019-01-08 13:21 ` Russell King - ARM Linux
2019-01-08 13:34 ` Daniel Vetter
2019-01-08 14:33 ` Andrzej Hajda
2019-01-08 15:07 ` Russell King - ARM Linux
2019-01-08 18:07 ` Daniel Vetter
2019-01-09 9:12 ` Andrzej Hajda
2019-01-09 9:24 ` Rafael J. Wysocki
2019-01-09 9:30 ` Russell King - ARM Linux
2019-01-11 14:20 ` Daniel Vetter
2019-01-11 14:26 ` Rafael J. Wysocki
2019-01-11 14:32 ` Russell King - ARM Linux
2019-01-11 14:36 ` Daniel Vetter
2019-01-11 14:40 ` Rafael J. Wysocki
2019-01-11 14:36 ` Rafael J. Wysocki
2019-01-11 14:49 ` Russell King - ARM Linux
2019-01-14 12:32 ` Rafael J. Wysocki
2019-01-15 0:04 ` Rafael J. Wysocki
2019-01-15 22:47 ` Rafael J. Wysocki
2019-01-16 18:42 ` Daniel Vetter
2019-01-16 22:43 ` Rafael J. Wysocki
2019-01-17 12:20 ` Daniel Vetter
2019-01-18 9:36 ` Lucas Stach
2019-01-18 10:03 ` Rafael J. Wysocki
2019-01-18 11:06 ` Daniel Vetter
2019-01-18 11:17 ` Rafael J. Wysocki
2019-01-18 11:37 ` Rafael J. Wysocki
2019-01-18 12:57 ` Daniel Vetter
2019-01-24 11:00 ` Rafael J. Wysocki
2019-01-17 17:26 ` Russell King - ARM Linux admin
2019-01-17 22:43 ` Rafael J. Wysocki
2019-01-18 11:07 ` Linus Walleij
2019-01-08 10:16 ` Russell King - ARM Linux
2019-01-08 10:31 ` Daniel Vetter
2019-01-07 16:12 ` Russell King - ARM Linux
2019-01-07 21:55 ` Daniel Vetter
2019-01-08 0:39 ` Russell King - ARM Linux
2019-01-08 14:29 ` Liviu Dudau
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