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Message-id: <542D3C96.7000400@samsung.com>
Date: Thu, 02 Oct 2014 13:52:54 +0200
From: Andrzej Hajda <a.hajda@samsung.com>
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To: Inki Dae <inki.dae@samsung.com>, Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        David Airlie <airlied@linux.ie>, Kukjin Kim <kgene.kim@samsung.com>,
        dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org, Thierry Reding <treding@nvidia.com>,
        Benjamin Gaignard <benjamin.gaignard@linaro.org>,
        Russell King <rmk+kernel@arm.linux.org.uk>,
        Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: Re: [PATCH] drm/exynos: fix vblank handling during dpms off
References: <542B9A0E.7020206@samsung.com>
 <1412151287-12845-1-git-send-email-a.hajda@samsung.com>
 <542D13CC.5000304@samsung.com> <542D2E7C.1020904@samsung.com>
In-reply-to: <542D2E7C.1020904@samsung.com>
Sender: linux-kernel-owner@vger.kernel.org

Hi,

+CC possible victims

On 10/02/2014 12:52 PM, Inki Dae wrote:
> On 2014년 10월 02일 17:58, Joonyoung Shim wrote:
>> Hi Andrzej,
>>
>> On 10/01/2014 05:14 PM, Andrzej Hajda wrote:
>>> The patch disables vblanks during dpms off only if pagefilp has
>>> not been finished. It also replaces drm_vblank_off with drm_crtc_vblank_put.
>>> It fixes issue with page_flip ioctl not being able to acquire vblank counter.
>> This problem isn't related with pageflip, it just causes from
>> 7ffd7a68511c710b84db3548a1997fd2625f580a commit (drm: Always reject
>> drm_vblank_get() after drm_vblank_off()).
>>
>> We need to use drm_vblank_on() as a counterpart to drm_vblank_off()
>> after the commit .

This patch should break also other drivers, it seems at least following
drms could be affected:
armada, sti, tegra.

I guess after disabling and re-enabling crtc vblanks should stop
working, unless there are other bugs.

Regards
Andrzej

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