From: Daniel Vetter <daniel@ffwll.ch>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-samsung-soc@vger.kernel.org,
Gustavo Padovan <gustavo.padovan@collabora.co.uk>,
dri-devel@lists.freedesktop.org, tjakobi@math.uni-bielefeld.de
Subject: Re: [PATCH] drm/exynos: only run atomic_check() if crtc is active
Date: Tue, 17 Nov 2015 11:06:11 +0100 [thread overview]
Message-ID: <20151117100611.GO16848@phenom.ffwll.local> (raw)
In-Reply-To: <20151112134929.GC645@ulmo>
On Thu, Nov 12, 2015 at 02:49:29PM +0100, Thierry Reding wrote:
> On Thu, Nov 12, 2015 at 11:11:20AM -0200, Gustavo Padovan wrote:
> > From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> >
> > Fixes an regression added by 3ae2436 (drm/exynos/mixer: replace
> > direct cross-driver call with drm mode). The whole atomic update
> > was failing if the hdmi display is not present/active. Add a test
> > to only run atomic_check() if the CRTC is active.
> >
> > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> > ---
> > drivers/gpu/drm/exynos/exynos_drm_crtc.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
> > index b3ba27f..1d3ca0a 100644
> > --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c
> > +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
> > @@ -55,6 +55,9 @@ static int exynos_crtc_atomic_check(struct drm_crtc *crtc,
> > {
> > struct exynos_drm_crtc *exynos_crtc = to_exynos_crtc(crtc);
> >
> > + if (!state->active)
> > + return 0;
> > +
> > if (exynos_crtc->ops->atomic_check)
> > return exynos_crtc->ops->atomic_check(exynos_crtc, state);
> >
>
> This looks like something that the core should be doing.
Nah, this is a bug in exynos atomic_check code. Drivers _must_ check state
irrespective of state->active - if they forgoe any checking when active =
false then legacy DPMS On might spuriuosly fail, which will upset
userspace. There shouldn't be any exceptions to this rule.
Cheers, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2015-11-17 10:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-12 13:11 [PATCH] drm/exynos: only run atomic_check() if crtc is active Gustavo Padovan
2015-11-12 13:49 ` Thierry Reding
2015-11-17 10:06 ` Daniel Vetter [this message]
2015-11-17 14:19 ` Andrzej Hajda
2015-11-17 16:12 ` Daniel Vetter
2015-11-20 9:15 ` 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=20151117100611.GO16848@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=gustavo.padovan@collabora.co.uk \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=thierry.reding@gmail.com \
--cc=tjakobi@math.uni-bielefeld.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