From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752976AbdAZIWf (ORCPT ); Thu, 26 Jan 2017 03:22:35 -0500 Received: from mailout2.w1.samsung.com ([210.118.77.12]:30002 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752664AbdAZIWd (ORCPT ); Thu, 26 Jan 2017 03:22:33 -0500 MIME-version: 1.0 Content-type: text/plain; charset=windows-1252 X-AuditID: cbfec7f5-f79d06d000004445-43-5889b1c5040a Subject: Re: [PATCH 6/7] drm/exynos/decon5433: signal vblank only on odd fields To: =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= Cc: Inki Dae , dri-devel@lists.freedesktop.org, Krzysztof Kozlowski , linux-samsung-soc@vger.kernel.org, Bartlomiej Zolnierkiewicz , linux-kernel@vger.kernel.org, Kyungmin Park , Marek Szyprowski , Daniel Vetter From: Andrzej Hajda Message-id: <51bd59d2-e0ca-f265-c90f-d68725602b44@samsung.com> Date: Thu, 26 Jan 2017 09:22:27 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 In-reply-to: <20170125140641.GU31595@intel.com> Content-transfer-encoding: 8bit X-Brightmail-Tracker: H4sIAAAAAAAAA01SbUhTYRTmvffu7rpcXafZQTNrGKGQGpVcTE3Bav/SKB3+MEdepqRTd9Wa CFmCuik5daCZyAymZZnfplKmU7cic4kjC2kiw4wS+hD7IJo17wL/Pec9z3Oe8xxeCpeYBAFU tqqQVasUOVJSRAxZftkOT/dq5ZF1y/uZ3qZuAbM5VIcz9o3PJFO/pCcYm61HyLy8sSZk5kdb SKbJNoYxXVPvhMwPVxsWL5I9+W4kZH2dWlLW+jxZtlRtxWQ3BzqRbL1vXxKZJorJZHOyi1l1 RFyGKGtG14LyK32uOkbuCsrQpFiHvCigj0GHVSvksT+8cnSTOiSiJLQJgXPmg6dYRzC0YkA6 RG0phm2e93YEVfavuFstpn3gZ4ODcGOcjoQmwyTGk94jsNtNpLvhSyfDbHkZcmM/OhHeDloF bhJOOzFYqa3c2oOkQ+FP/1uSnxoH111LmBsT9EFoufVQ4Ma7aTmYLYtbzl50BDSaawS8czBM 2FcJ91CgLUKoXHTg/NpB0DeO8zkToaJhmeSxL3y0Dnjy7wVt1QTGa6sRfKt9JuQLAwLXlyaP +gRMWuc8bjuhfqjRYyCGqgoJT5GB3XXbQ0+ArvZPWwEk9AwGPXcIPQpu3nax5m0Xa96WwYjw TuTHFnG5SpY7Hs4pcrkilTL8Ul5uH/r3eV64rBvDyGSJNiOaQlJv8fhwlVwiUBRzmlwzAgqX +olt97VyiThToSlh1XkX1UU5LGdGgRQh3SN+bLSnSmilopC9zLL5rPp/F6O8AsqQ1TYfnTA3 K35wKiXstCi2tjSpSOmvPzQ7FlXXxs3BgmbAHJM6vXrudfrCiMB5wJCWV1Bnp7XTBfKFkfrm rpDxs1mlhqALNYGxRv38Gc1axm+GfdRgPOpaHb13pSNqs3/wqfeOa6b4jdD2Xst5mAsPUaVP lbS+iT7ZP59S7twlJbgsxZEwXM0p/gKvptxFOAMAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrIIsWRmVeSWpSXmKPExsVy+t/xq7qsmzojDH5uZrbYOGM9q8X/bROZ La58fc9mMen+BBaL8+c3sFucbXrDbnF51xw2ixnn9zFZrD1yl93i+7+FTA5cHnu/LWDx2LSq k81j3slAj/vdx5k8+rasYvT4vEkugC3KzSYjNTEltUghNS85PyUzL91WKTTETddCSSEvMTfV VilC1zckSEmhLDGnFMgzMkADDs4B7sFK+nYJbhlnuuYwFrQLVtzbuYK1gfEwbxcjB4eEgInE jvNsXYycQKaYxIV768FsIYEljBKdDcUgNq+AoMSPyfdYQMqZBfQk7l/U6mLkAip5xiix6Pcv ZpAaYQF/ia/z/oLZIgIuEje3HmeFKDrDJNHx5RwziMMs8BjIednGClLFJqAp8XfzTTaIDXYS jf/uM4HYLAKqEnNmrmMF2SYqECHRcDgdJMwpoC8x/VAPWCuzgLzEwSvPWSYwCsxCct8shPtm IalawMi8ilEktbQ4Nz232FCvODG3uDQvXS85P3cTIzD6th37uXkH46WNwYcYBTgYlXh4D+zo iBBiTSwrrsw9xCjBwawkwnt+dWeEEG9KYmVValF+fFFpTmrxIUZToFMnMkuJJucDE0NeSbyh iaG5paGRsYWFuZGRkjhvyYcr4UIC6YklqdmpqQWpRTB9TBycUg2MnWrvkhzk1sfveZT/uFWB W0LqeEmxjNheFuM9MqJTkxd4WKRrTEn8sy9c6azAoS7VE3kvnwbbVbTPnfzf7Z+F/S/nyYvW ceszS7292PXHO6T4enNKtpxfT9lq5Qt1V3Nl/8+wWPc4h9kpP9mh89Cax3d9nRgFvHky7hx7 wSEfYLwpbt5Sx3glluKMREMt5qLiRADppnTW1AIAAA== X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20170126082229eucas1p138a5a15565c04d623a7831790d514b67 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> <1484895145-511-7-git-send-email-a.hajda@samsung.com> <20170120135540.GC31595@intel.com> <953193f0-484e-0457-baf4-e42b44a3f147@samsung.com> <20170125140641.GU31595@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25.01.2017 15:06, Ville Syrjälä wrote: > On Mon, Jan 23, 2017 at 10:15:16AM +0100, Andrzej Hajda wrote: >> 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. > That's very typical for us unfortunately. > > I would say what we should do what i915 does. It allows more flexibility > in how you use the hardware. Eg. then you can actually scan out > interlaced material to an interlaced display and not mess up the fields, > and you can also do 3:2 pulldown type of stuff. Or you can even just > stuff progressive frames down the pipe at field rate. > > One problem with interlaced stuff is that we don't have any field > indication in the events, nor do we have a way to flip on a specific > field. I tried to specify the latter for the SETPLANE ioctl way > back when, but it didn't end up being implemented and now we would > need something different for atomic. > >> 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. > Each field has a proper vertical blanking interval, so you'd just end up > totally wasting one of them. The problem in this particular case is that hardware does not allow to change buffers between fields, or more precisely it updates its internal registers after 2nd field - ie after reading full frame. I am still investigating the issue, but it is possible this limitation cannot be overcome. Regards Andrzej > >> 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