From: Daniel Vetter <daniel@ffwll.ch>
To: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>,
Andrzej Hajda <a.hajda@samsung.com>,
Daniel Vetter <daniel.vetter@intel.com>,
David Airlie <airlied@linux.ie>, Sam Ravnborg <sam@ravnborg.org>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Thomas Zimmermann <tzimmermann@suse.de>,
Neil Armstrong <narmstrong@baylibre.com>,
Jonas Karlman <jonas@kwiboo.se>,
Jernej Skrabec <jernej.skrabec@gmail.com>,
Thierry Reding <thierry.reding@gmail.com>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 04/10] drm/bridge: Document the probe issue with MIPI-DSI bridges
Date: Tue, 27 Jul 2021 11:20:54 +0200 [thread overview]
Message-ID: <YP/P9rJrZyk6zjsT@phenom.ffwll.local> (raw)
In-Reply-To: <20210726151657.c46qmkdvqfhlg6ox@gilmour>
On Mon, Jul 26, 2021 at 05:16:57PM +0200, Maxime Ripard wrote:
> Hi Daniel,
>
> On Wed, Jul 21, 2021 at 02:05:01PM +0200, Daniel Vetter wrote:
> > On Tue, Jul 20, 2021 at 03:45:19PM +0200, Maxime Ripard wrote:
> > > Interactions between bridges, panels, MIPI-DSI host and the component
> > > framework are not trivial and can lead to probing issues when
> > > implementing a display driver. Let's document the various cases we need
> > > too consider, and the solution to support all the cases.
> > >
> > > Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> >
> > I still have this dream that eventually we resurrect a patch to add
> > device_link to bridges/panels (ideally automatically), to help with some
> > of the suspend/resume issues around here.
> >
> > Will this make things worse?
> >
> > I think it'd be really good to figure that out with some coding, since if
> > we have incompatible solution to handle probe issues vs suspend/resume
> > issues, we're screwed.
> >
> > Atm the duct-tape is to carefully move things around between suspend and
> > suspend_early hooks (and resume and resume_late) and hope it all works ...
>
> My initial idea to fix this was indeed to use device links. I gave up
> after a while since it doesn't look like there's a way to add a device
> link before either the bridge or encoder probes.
>
> Indeed the OF-Graph representation is device-specific, so it can't be
> generic, and if you need to probe to add that link, well, it's already
> too late for the probe ordering :)
But don't we still need the device_link for suspend/resume and module
reload? All very annoying indeed anyway.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2021-07-27 9:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-20 13:45 [PATCH 00/10] drm/bridge: Make panel and bridge probe order consistent Maxime Ripard
2021-07-20 13:45 ` [PATCH 01/10] Revert "drm/vc4: dsi: Only register our component once a DSI device is attached" Maxime Ripard
2021-07-20 13:45 ` [PATCH 02/10] drm/bridge: Add a function to abstract away panels Maxime Ripard
2021-07-22 7:49 ` Jagan Teki
2021-07-20 13:45 ` [PATCH 03/10] drm/bridge: Add documentation sections Maxime Ripard
2021-07-20 13:45 ` [PATCH 04/10] drm/bridge: Document the probe issue with MIPI-DSI bridges Maxime Ripard
2021-07-21 12:05 ` Daniel Vetter
2021-07-21 12:06 ` Daniel Vetter
2021-07-26 15:16 ` Maxime Ripard
2021-07-27 9:20 ` Daniel Vetter [this message]
2021-07-28 13:27 ` Maxime Ripard
2021-07-27 9:42 ` Jagan Teki
2021-07-28 13:35 ` Maxime Ripard
2021-08-05 12:19 ` Jagan Teki
2021-07-20 13:45 ` [PATCH 05/10] drm/panel: Create attach and detach callbacks Maxime Ripard
2021-07-22 7:53 ` Jagan Teki
2021-07-20 13:45 ` [PATCH 06/10] drm/bridge: panel: Call attach and detach for the panel Maxime Ripard
2021-07-20 13:45 ` [PATCH 07/10] drm/vc4: dsi: Switch to drm_of_get_next Maxime Ripard
2021-07-20 13:45 ` [PATCH 08/10] drm/panel: raspberrypi-touchscreen: Prevent double-free Maxime Ripard
[not found] ` <YPcFrKLq1dhTcOUL@ravnborg.org>
2021-07-22 9:38 ` Maxime Ripard
2021-07-20 13:45 ` [PATCH 09/10] drm/panel: raspberrypi-touchscreen: Use the attach hook Maxime Ripard
2021-07-20 13:45 ` [PATCH 10/10] drm/panel: raspberrypi-touchscreen: Remove MIPI-DSI driver 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=YP/P9rJrZyk6zjsT@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=Laurent.pinchart@ideasonboard.com \
--cc=a.hajda@samsung.com \
--cc=airlied@linux.ie \
--cc=daniel.vetter@intel.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=jernej.skrabec@gmail.com \
--cc=jonas@kwiboo.se \
--cc=linux-kernel@vger.kernel.org \
--cc=maarten.lankhorst@linux.intel.com \
--cc=maxime@cerno.tech \
--cc=narmstrong@baylibre.com \
--cc=robert.foss@linaro.org \
--cc=sam@ravnborg.org \
--cc=thierry.reding@gmail.com \
--cc=tzimmermann@suse.de \
/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).