From: Thierry Reding <thierry.reding@gmail.com>
To: Andrzej Hajda <a.hajda@samsung.com>
Cc: dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm/exynos/dsi: simplify hotplug code
Date: Thu, 6 Nov 2014 14:18:27 +0100 [thread overview]
Message-ID: <20141106131824.GC12260@ulmo> (raw)
In-Reply-To: <1415273748-26805-1-git-send-email-a.hajda@samsung.com>
[-- Attachment #1.1: Type: text/plain, Size: 1471 bytes --]
On Thu, Nov 06, 2014 at 12:35:48PM +0100, Andrzej Hajda wrote:
> Exynos DSI driver uses DSI bus attach/detach callbacks to implement
> panel hotplug mechanism. The patch moves panel attachment code
> from .detect callback to DSI bus callbacks. It makes the code
> simpler and more straightforward.
> The patch removes also redundant and lock unprotected dpms_off call
> from unbind code.
>
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> ---
> Hi,
>
> This patch simplifies drm part of hotplug mechanism in dsi attach/detach callbacks.
> It also fixes minor bug with unprotected dpms_off call, which is unneccesary anyway.
>
> But the main reason I have looked at this code again is to show that
> we do not need zombie panels, we can kill panels properly if we have hot plug/unplug
> callbacks. And it is quite simple: we just need to take mode_config.mutex locks
> to synchronize dsi callbacks with drm, nothing more.
> It works nicely because of two things:
> - panel callbacks are called always under this lock,
> - callbacks are installed after drmdev creation and deinstalled before drmdev destroy -
> this way we assure drmdev is always present in callbacks.
Again, something like what you propose is going to work only for DSI
devices. What we need is a solution that works for all other types of
panels, too. This is even more important when we consider bridges
because they are less likely to be on a DSI bus.
Thierry
[-- Attachment #1.2: Type: application/pgp-signature, Size: 819 bytes --]
[-- Attachment #2: Type: text/plain, Size: 159 bytes --]
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2014-11-06 13:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-06 11:35 [PATCH] drm/exynos/dsi: simplify hotplug code Andrzej Hajda
2014-11-06 13:18 ` Thierry Reding [this message]
2014-11-06 13:30 ` Andrzej Hajda
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=20141106131824.GC12260@ulmo \
--to=thierry.reding@gmail.com \
--cc=a.hajda@samsung.com \
--cc=dri-devel@lists.freedesktop.org \
/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