From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A8A9C169C4 for ; Sun, 3 Feb 2019 20:57:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 154C220821 for ; Sun, 3 Feb 2019 20:57:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dhZkOSkv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727740AbfBCU5M (ORCPT ); Sun, 3 Feb 2019 15:57:12 -0500 Received: from mail-qt1-f193.google.com ([209.85.160.193]:44922 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727088AbfBCU5M (ORCPT ); Sun, 3 Feb 2019 15:57:12 -0500 Received: by mail-qt1-f193.google.com with SMTP id n32so13430046qte.11 for ; Sun, 03 Feb 2019 12:57:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=x2X8y1DrqWl8MJKwH+RgIo7D7U+ZYN5MLly5SAkB7M4=; b=dhZkOSkvPAFNWh+Q94DbTeuEohXmvCPxShTmyeSn128gKNd7TgiybFB/RHi+0KVjV2 BtAwW5r1PqyrIM5mL+y3sqWo9u1Mk8qx7fF8eLAAit7tS3s+SwqHcoZqpH35r8SO+AUi zouTPRwsAZNEx65uCwBb7HwU/cPlcoeLFu+0EHxcU1PneLeMfZDmZgFPiXNHLp+lb6vo NwZ04SSnS6bYslt7IV9dILitRyp2Vub+qBSogPRRVNHReJT3oJJ9nIFJaW4a6iAYubZX EAj/uYZfeHfLT0WfdcAhDKHjcOVFR/8tRepq8F5wh7pyDR3xUQKfNB/eCeoF+LdJypK2 iwnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=x2X8y1DrqWl8MJKwH+RgIo7D7U+ZYN5MLly5SAkB7M4=; b=ud5Quj8365OUeSpT+9gEoPKl++Z1qpGOAAnYmFhYZ3Y20b4NgH0ddntE91wBeQsuqM jj2m+VohTQ4tqNp19QuK0F14jEZtfDTDcvB0/2oTbqiJZ/zE5OHeHXI+mmVJBFFjqYcW o4O+G4OxwEAvc9vJjFGFnAlRXRBzAWjV1suTEIORLqPMPg0BtUdS/dp74KvkdwdGebB+ 5uZSkkcai/rwBaLV/MzJ5hwCZQtqTBpizgX6agq+b/oF0epQ1ff6SL3v5wf6QdQ6/7cQ k+t5UmJnJvP2gstw83HteEOygJPpZ4S//h4H+t15AGsSDKZWZtRmDCdNfVx/vxy4l6zm roRA== X-Gm-Message-State: AJcUukehr9LIcxINLIAzN/Qcln3UG/s8Rfd7cMWprK8/pK+MI22m5GJ2 FGmTkMeamh0KFuFu/NX/yIg= X-Google-Smtp-Source: ALg8bN6DHbfby4F3oWsU1HHXUbktkoGUpaR/8P/vd9Hg+sKapmTiR0GO0phJbK2qZmwA44sCUeroQw== X-Received: by 2002:aed:306c:: with SMTP id 99mr46206080qte.61.1549227430442; Sun, 03 Feb 2019 12:57:10 -0800 (PST) Received: from smtp.gmail.com ([143.107.45.1]) by smtp.gmail.com with ESMTPSA id b27sm4550398qkj.17.2019.02.03.12.57.08 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 03 Feb 2019 12:57:09 -0800 (PST) Date: Sun, 3 Feb 2019 18:57:07 -0200 From: Rodrigo Siqueira To: Shayenne Moura Cc: Haneen Mohammed , Daniel Vetter , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] drm/vkms: Bugfix extra vblank frame Message-ID: <20190203205707.7pqv6s5xuhbxduqv@smtp.gmail.com> References: <171e6e1c239cbca0c3df7183ed8acdfeeace9cf4.1548856186.git.shayenneluzmoura@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="kojcgas5cotmjhuj" Content-Disposition: inline In-Reply-To: <171e6e1c239cbca0c3df7183ed8acdfeeace9cf4.1548856186.git.shayenneluzmoura@gmail.com> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --kojcgas5cotmjhuj Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 01/30, Shayenne Moura wrote: > kms_flip tests are breaking on vkms when simulate vblank because vblank > event sequence count returns one extra frame after arm vblank event to > make a page flip. >=20 > When vblank interrupt happens, userspace processes the vblank event and > issues the next page flip command. Kernel calls queue_work to call > commit_planes and arm the new page flip. The next vblank picks up the > newly armed vblank event and vblank interrupt happens again. >=20 > The arm and vblank event are asynchronous, then, on the next vblank, we > receive x+2 from `get_vblank_timestamp`, instead x+1, although timestamp > and vblank seqno matches. >=20 > Function `get_vblank_timestamp` is reached by 2 ways: >=20 > - from `drm_mode_page_flip_ioctl`: driver is doing one atomic operation > to synchronize planes in the same output. There is no vblank simulati= on, > the `drm_crtc_arm_vblank_event` function adds 1 on vblank count, and = the > variable in_vblank_irq is false > - from `vkms_vblank_simulate`: since the driver is doing a vblank simul= ation, > the variable in_vblank_irq is true. >=20 > Fix this problem subtracting one vblank period from vblank_time when > `get_vblank_timestamp` is called from trace `drm_mode_page_flip_ioctl`, > i.e., is not a real vblank interrupt, and getting the timestamp and vblank > seqno when it is a real vblank interrupt. >=20 > The reason for all this is that get_vblank_timestamp always supplies the > timestamp for the next vblank event. The hrtimer is the vblank simulator, > and it needs the correct previous value to present the next vblank. Since > this is how hw timestamp registers work and what the vblank core expects. >=20 > Signed-off-by: Shayenne Moura > Signed-off-by: Daniel Vetter >=20 > --- > drivers/gpu/drm/vkms/vkms_crtc.c | 3 +++ > 1 file changed, 3 insertions(+) >=20 > diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms= _crtc.c > index d44bfc392491..23146ff2a25b 100644 > --- a/drivers/gpu/drm/vkms/vkms_crtc.c > +++ b/drivers/gpu/drm/vkms/vkms_crtc.c > @@ -87,6 +87,9 @@ bool vkms_get_vblank_timestamp(struct drm_device *dev, = unsigned int pipe, > =20 > *vblank_time =3D output->vblank_hrtimer.node.expires; > =20 > + if (!in_vblank_irq) > + *vblank_time -=3D output->period_ns; > + > return true; > } > =20 > --=20 > 2.17.1 >=20 Reviewed-by: Rodrigo Siqueira --=20 Rodrigo Siqueira https://siqueira.tech Graduate Student Department of Computer Science University of S=E3o Paulo --kojcgas5cotmjhuj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE4tZ+ii1mjMCMQbfkWJzP/comvP8FAlxXVaIACgkQWJzP/com vP/Uow//Vu98UqGq6ZmhdIx+tQ7ZtMhKOXDtACHTqLA1+DKR+DIObYmVl41BkwlR c8IthbpMsG9bwlmhZH5j9tunZwoysT+iRSLQ3GCih3j8esEyXFITD4zgzEIXK4en mYx2bCjZvmng6zL/4L3TDnNXZYWCoiCeOMmtRR9cuil4Fm6M938w5O2wCbDj0Ut8 Q3pb9qTDk3uROT7EFRZ7BgGfZ5krK4Gr5MzZUi3VgujhKkDr/nIl0Tkc/LUafrbX 9u7PDNPHF+SASTuL4sY+JdPXCFYjdjq8pzxjwfGvfh4sH8wp/YIspXGaZjG2Ni4M HewmifLCgC3AT7Da7LmySAORm8pvryMfwT8AmXupMlCw3V531U84/jGGmO4Pk2Q1 scbLO0Lx+xVPhOkc6+kPRb33e4582NwaLu8oMOAh8qbX4FYCslDuJz0JUBiQN7+K zcqC9iU+SY5h0eoHhO14Y7KfJJukdn/Ro4HhWnDmwdgrJJ2ZyDJaMzBrAYDw6+DP +hhKtdDttQTL1EwVSvj/IAXipB3JzaCLKtQFKTcUm/AI2ueRkhEoTq4qtc5Dy775 xHvMXqizNcvvyC34UioPWelmU0nORYIXkgGt7P1EYmR0DF9F5h+K7SdpX1YESyHX JVKJOkNAbZ2vwET9F7wdDpFhQlCBKLsuaR4gE1ILXhhrBqCNcjg= =MjX9 -----END PGP SIGNATURE----- --kojcgas5cotmjhuj--