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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 DA700C2D0A8 for ; Wed, 23 Sep 2020 11:14:53 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A31A720725 for ; Wed, 23 Sep 2020 11:14:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A31A720725 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 02FDC6E962; Wed, 23 Sep 2020 11:14:50 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9CE706E960; Wed, 23 Sep 2020 11:14:48 +0000 (UTC) Received: from xpredator (unknown [IPv6:2a02:2f08:4c14:a400:24d7:51ff:fed6:906d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: mvlad) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 2885629C364; Wed, 23 Sep 2020 12:14:47 +0100 (BST) Date: Wed, 23 Sep 2020 14:14:43 +0300 From: Marius Vlad To: Daniel Vetter Message-ID: <20200923111443.GA8478@xpredator> References: <20180705101043.4883-1-daniel.vetter@ffwll.ch> <20180705102121.5091-1-daniel.vetter@ffwll.ch> <20200922133636.GA2369@xpredator> MIME-Version: 1.0 In-Reply-To: Subject: Re: [Intel-gfx] [PATCH] drm: avoid spurious EBUSY due to nonblocking atomic modesets X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Intel Graphics Development , DRI Development , stable , Daniel Vetter , Pekka Paalanen Content-Type: multipart/mixed; boundary="===============1516733958==" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" --===============1516733958== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="RnlQjJ0d97Da+TV1" Content-Disposition: inline --RnlQjJ0d97Da+TV1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 23, 2020 at 12:58:30PM +0200, Daniel Vetter wrote: > On Tue, Sep 22, 2020 at 3:36 PM Marius Vlad w= rote: > > > > On Fri, Jan 31, 2020 at 07:34:00AM +0000, Daniel Stone wrote: > > > On Thu, 5 Jul 2018 at 11:21, Daniel Vetter w= rote: > > > > When doing an atomic modeset with ALLOW_MODESET drivers are allowed= to > > > > pull in arbitrary other resources, including CRTCs (e.g. when > > > > reconfiguring global resources). > > > > > > > > But in nonblocking mode userspace has then no idea this happened, > > > > which can lead to spurious EBUSY calls, both: > > > > - when that other CRTC is currently busy doing a page_flip the > > > > ALLOW_MODESET commit can fail with an EBUSY > > > > - on the other CRTC a normal atomic flip can fail with EBUSY because > > > > of the additional commit inserted by the kernel without userspace= 's > > > > knowledge > > > > > > > > For blocking commits this isn't a problem, because everyone else wi= ll > > > > just block until all the CRTC are reconfigured. Only thing userspace > > > > can notice is the dropped frames without any reason for why frames = got > > > > dropped. > > > > > > > > Consensus is that we need new uapi to handle this properly, but no = one > > > > has any idea what exactly the new uapi should look like. As a stop-= gap > > > > plug this problem by demoting nonblocking commits which might cause > > > > issues by including CRTCs not in the original request to blocking > > > > commits. > > Gentle ping. I've tried out Linus's master tree and, and like Pekka, > > I've noticed this isn't integrated/added. > > > > Noticed this is fixing (also) DPMS when multiple outputs are in use. > > Wondering if we can just use a _ONCE() variant instead of WARN_ON(). I'= m seeing > > the warning quite often. >=20 > On which driver/chip does this happen? I've tried it out on i915. > -Daniel >=20 > > > > > > > > Thanks for writing this up Daniel, and for reminding me about it some > > > time later as well ... > > > > > > Reviewed-by: Daniel Stone > > > > > > Cheers, > > > Daniel > > > _______________________________________________ > > > dri-devel mailing list > > > dri-devel@lists.freedesktop.org > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel >=20 >=20 >=20 > --=20 > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch --RnlQjJ0d97Da+TV1 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEcDKHej6x6uPk3J379jQS5glH1u8FAl9rLiAACgkQ9jQS5glH 1u8bSxAAqdQ/WtRkNdIfWUw7AI0LWFLlPvcZxqgPN5pgZRHHuXPCjCwtiXLyiyHW RotgvgPcLFfnxJ6jR8VAwkDp+J052yDidV2L5j10mvWIHzh3PCWYw/kJKovejCtQ rE6hBktEMbKaQhWX0AysPQvlzLO8JFfXMuC/0Ubva19X85LZvlYfUA2ulfUAdStY N+vlp5s3V3XO0bvGf1nmOm1W12I3G++egVs2KkTg0kW7OTlsqUhTlBkhSCRGGiCP 4PKY+X7J1Nfn44QYfvMmoZGwsbMX1JxYIJWoKc7SB/d9UDCN2s743BdJw6XxbIZ2 x7KJf6rTd3eh1YACSvDpZZf1b+h10SyAKmoIh5zitMlhCtUT7iywCHu0R/WMva7O u/Sk+sAs02t+U8mpQywlNiZnrf8B2COjm/RSdCZWpBSoR+x69yVF9fULA99kVDaZ tH5CrMdtgKcue/8Dc9ckVKbVrAPhly6tjo4Hwkx0hJ5u+0R04GLqMHVg/snRYDpW j/PEddhpaXtvgL+UDLGUYCsURfVD0lGmHruHV7XA9wOhSmeSH/ySgcd3Uys0saFD Ih6mCZHCFOwYXx0JBRvTgpbq8EIndjgbkoNw8/xWp9RMV/W6evI9YwkcRY7jLcZw OdMunC3GeeMED3CtJq57vwMuvucCAKd2kAb7FL1YhupAcbGmb2c= =xLmh -----END PGP SIGNATURE----- --RnlQjJ0d97Da+TV1-- --===============1516733958== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx --===============1516733958==--