From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751093AbdAWJP3 (ORCPT <rfc822;w@1wt.eu>);
        Mon, 23 Jan 2017 04:15:29 -0500
Received: from mailout2.w1.samsung.com ([210.118.77.12]:17550 "EHLO
        mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1751013AbdAWJP0 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 23 Jan 2017 04:15:26 -0500
MIME-version: 1.0
Content-type: text/plain; charset=windows-1252
X-AuditID: cbfec7f1-f793f6d000007796-9c-5885c9a52f93
Subject: Re: [PATCH 6/7] drm/exynos/decon5433: signal vblank only on odd fields
To: =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= <ville.syrjala@linux.intel.com>
Cc: Inki Dae <inki.dae@samsung.com>, dri-devel@lists.freedesktop.org,
        Krzysztof Kozlowski <krzk@kernel.org>,
        linux-samsung-soc@vger.kernel.org,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        linux-kernel@vger.kernel.org,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Daniel Vetter <daniel@ffwll.ch>
From: Andrzej Hajda <a.hajda@samsung.com>
Message-id: <953193f0-484e-0457-baf4-e42b44a3f147@samsung.com>
Date: Mon, 23 Jan 2017 10:15:16 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
        Thunderbird/45.5.1
In-reply-to: <20170120135540.GC31595@intel.com>
Content-transfer-encoding: 8bit
X-Brightmail-Tracker: H4sIAAAAAAAAA02SfyyUcRzH+z7Pc8/zuLn2ONInFF3rj2qh1tazyIS1W3+09EdZ/cGVx49x
        2D0oWRsiP4fQuqmJLdY04UiIjmOOrjrcbYUwC21K5LdNynnO5r/Xe5/3+/PZ57MPjUurRE50
        ZEw8p4pRRMtIMdHUs248WdmXEeQ5menJ1qtrRey/pkc4a16eI9mi8UKCNRrrKPZT2i+KNbU+
        I1m18T3G1nSPUuzqZgXmK5a3r5QTck11Nikv6wuUj+fqMXl+YzWSL2oOXSFviL1DuejIRE7l
        4RMijpifDI6bJe9u9K1RKahVlINsaGDOQJG6zMqO0D9WS+YgMS1lKhEYdVokiEUEHfoRcieh
        1X6hhEIVgtn0xu24hLGDteIxwsI44wnqki5MME0jeGzQbZvsmUD4/CAFWdiBCYChN3qRxYQz
        3zGYKsikLAWSOQZ/G4ZIoasP1FXObHclmKNQ1paPWXgfEwS6nhHcwjaMBwy2l1knu0Kn+Qdh
        aQrMBwpSh1O2BL0lDoKmAxdWCIDRvApCYHuY0TdSArtAdlYnJmRzESwU9FKCKEGwOa+2pr2g
        Sz8gEqbthaKmJ7gwQAJZD6WCRQ7mzadW+wWoqfppPcUCgvVXg1ghci3ddbLSXScr3bVEOcKr
        kQOXwCvDOf60O69Q8gkx4e63Y5UatPU9hk39n2Y013tOhxgayWwlzFR6kFSkSOSTlDoENC5z
        kPR1ZgRJJaGKpHucKjZYlRDN8TrkTBOy/ZK2cvN1KROuiOeiOC6OU+1UMdrGKQW5pb/zej6Y
        tmoIyyE2PjqHNThFmYaLu23761dnzt4stfMzv4z1P+zvobFNYk3iPPC+461dPnA1PL5uouUy
        /+L1kik5q97n2v2JaUPtkdzUXLe3XobOGJeQ5FttHhB9yfGi34o60PDbu6egYLhpgKw+4bv0
        dd0eNX9r0Z4vDzTvkRF8hOLUcVzFK/4DB8+IezkDAAA=
X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrEIsWRmVeSWpSXmKPExsVy+t/xq7qPTrZGGJx+rGuxccZ6Vov/2yYy
        W1z5+p7NYtL9CSwW589vYLc42/SG3eLyrjlsFjPO72OyWHvkLrvF938LmRy4PPZ+W8DisWlV
        J5vHvJOBHve7jzN59G1ZxejxeZNcAFuUm01GamJKapFCal5yfkpmXrqtUmiIm66FkkJeYm6q
        rVKErm9IkJJCWWJOKZBnZIAGHJwD3IOV9O0S3DI+PIkveMtW8efkD/YGxl2sXYycHBICJhL7
        919nh7DFJC7cW8/WxcjFISSwhFFi2d7rYEW8AoISPybfY+li5OBgFtCTuH9RC6LmGaPEwb7t
        bCA1wgL+El/n/WUGsUUEXCRubj3OClH0iVHi8sm/TCAOs8BjJomOl21gU9kENCX+br7JBrHB
        TmLD0lcsIDaLgKrEvD19TCDbRAUiJBoOp4OEOQX0JS7tnQdWwiwgL3HwynOWCYwCs5DcNwvh
        vllIqhYwMq9iFEktLc5Nzy021CtOzC0uzUvXS87P3cQIjL9tx35u3sF4aWPwIUYBDkYlHl6B
        py0RQqyJZcWVuYcYJTiYlUR4Tx5sjRDiTUmsrEotyo8vKs1JLT7EaAp06kRmKdHkfGBqyCuJ
        NzQxNLc0NDK2sDA3MlIS5y35cCVcSCA9sSQ1OzW1ILUIpo+Jg1OqgZHRwHeiaMmc9dnfJss9
        tb2eNO3i46ndv7tMebc9OjTZX8dmusTdG4lX7+992VdgOaP3oY6fiAfbdeYrdsGhyqXp7Xff
        bXY7e4I1tYDTN6ds8uze79dq9P8mv54us6cw4I/ep/o5esnBl3MVVf9lfpqZvHHXzlnts1VO
        OOg98zr3yvFRr6frjCtKLMUZiYZazEXFiQAJ9EQ41QIAAA==
X-MTR: 20000000000000000@CPGS
X-CMS-MailID: 20170123091517eucas1p1e84189201bfd89e9f7533b0dfb4b564e
X-Msg-Generator: CA
X-Sender-IP: 182.198.249.179
X-Local-Sender: =?UTF-8?B?QW5kcnplaiBIYWpkYRtTUlBPTC1LZXJuZWwgKFRQKRvsgrw=?=
        =?UTF-8?B?7ISx7KCE7J6QG1NlbmlvciBTb2Z0d2FyZSBFbmdpbmVlcg==?=
X-Global-Sender: =?UTF-8?B?QW5kcnplaiBIYWpkYRtTUlBPTC1LZXJuZWwgKFRQKRtTYW1z?=
        =?UTF-8?B?dW5nIEVsZWN0cm9uaWNzG1NlbmlvciBTb2Z0d2FyZSBFbmdpbmVlcg==?=
X-Sender-Code: =?UTF-8?B?QzEwG0VIURtDMTBDRDAyQ0QwMjczOTI=?=
CMS-TYPE: 201P
X-HopCount: 7
X-CMS-RootMailID: 20170120065231eucas1p121d2a987695fdce00e1b2bba445f1818
X-RootMTR: 20170120065231eucas1p121d2a987695fdce00e1b2bba445f1818
References: <1484895145-511-1-git-send-email-a.hajda@samsung.com>
 <CGME20170120065231eucas1p121d2a987695fdce00e1b2bba445f1818@eucas1p1.samsung.com>
 <1484895145-511-7-git-send-email-a.hajda@samsung.com>
 <20170120135540.GC31595@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 20.01.2017 14:55, Ville Syrjälä wrote:
> On Fri, Jan 20, 2017 at 07:52:24AM +0100, Andrzej Hajda wrote:
>> In case of interlace mode irq is generated for odd and even fields, but
>> vblank should be signaled only for the last emitted field.
> I'm pretty sure most drivers signal it for both fields. At least i915
> does.

The question is which behavior is correct? I have not found any clear
statement in the documentation, or drm core code.
I have guessed that since vblank event is used to signal end of scan-out
of buffer it should be called after scan-out of whole buffer - in case
of interlaced mode after scan-out of 2nd field.
Maybe my assumption is wrong, in such case this patch should be dropped
and mixer driver also should be fixed, but before doing that it would be
good to know for sure how it should be handled correctly.

Regards
Andrzej