public inbox for linux-rt-users@vger.kernel.org
 help / color / mirror / Atom feed
From: Jani Nikula <jani.nikula@linux.intel.com>
To: David Weinehall <tao@kernel.org>
Cc: Nicolae Rosia <nicolae.rosia.oss@gmail.com>,
	"linux-rt-users\@vger.kernel.org"
	<linux-rt-users@vger.kernel.org>,
	dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] i915 monitor hotplug on 4.1/4.4 PREEMPT
Date: Thu, 20 Oct 2016 17:08:50 +0300	[thread overview]
Message-ID: <87h987qfil.fsf@intel.com> (raw)
In-Reply-To: <20161020125708.GB8202@suiko.acc.umu.se>

On Thu, 20 Oct 2016, David Weinehall <tao@kernel.org> wrote:
> On Thu, Oct 20, 2016 at 03:28:10PM +0300, Jani Nikula wrote:
>> On Thu, 20 Oct 2016, Nicolae Rosia <nicolae.rosia.oss@gmail.com> wrote:
>> > Monitor hotplugging seems to be broken on latest 4.1/4.4 RT kernel with i915.
>> > I have tested this on non-RT kernel and it works.
>
> The answer to your first question seems to be here :)

*blush*

>> > I get an udev event for unplugging, but there's no event generated for
>> > plugging the monitor back in.
>> 
>> Does it work on non-RT? Does it work on v4.8 or v4.9-rc1?
>
> The second one is relevant though. 4.1 is pre-historic, 4.4 is ancient.

I think the honest answer here is that we do not have the resources to
debug RT vs. non-RT issues all that much in general, and especially not
for such old kernels. RT is not in our focus, and hotplug has proved to
be hard enough on non-RT. Nothing to be proud of, but we have 500+ bugs
open over at the freedesktop.org bugzilla, most for relatively recent
non-RT kernels.

Even if we fixed this upstream (and it would have to be fixed upstream
to be backported) it's a huge problem that the feedback loop for RT
kernels has such a long delay. If we break something for RT, it takes
forever for us to find out.


BR,
Jani.

-- 
Jani Nikula, Intel Open Source Technology Center

  reply	other threads:[~2016-10-20 14:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-20 12:15 i915 monitor hotplug on 4.1/4.4 PREEMPT Nicolae Rosia
2016-10-20 12:28 ` Jani Nikula
2016-10-20 12:57   ` David Weinehall
2016-10-20 14:08     ` Jani Nikula [this message]
2016-10-20 14:09     ` [Intel-gfx] " Nicolae Rosia
2016-10-21 12:27       ` Daniel Vetter
2016-10-21 13:21         ` Nicolae Rosia
2016-10-21 18:14           ` Daniel Vetter

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=87h987qfil.fsf@intel.com \
    --to=jani.nikula@linux.intel.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=nicolae.rosia.oss@gmail.com \
    --cc=tao@kernel.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