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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 8BCCDC433C1 for ; Tue, 23 Mar 2021 10:20:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68FE0619BA for ; Tue, 23 Mar 2021 10:20:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229504AbhCWKUG (ORCPT ); Tue, 23 Mar 2021 06:20:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbhCWKTy (ORCPT ); Tue, 23 Mar 2021 06:19:54 -0400 Received: from mail-ed1-x530.google.com (mail-ed1-x530.google.com [IPv6:2a00:1450:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09EDDC061574 for ; Tue, 23 Mar 2021 03:19:54 -0700 (PDT) Received: by mail-ed1-x530.google.com with SMTP id l18so14598475edc.9 for ; Tue, 23 Mar 2021 03:19:53 -0700 (PDT) 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=oAc0syotsHDUnWyUjFLewhBpFhavjrYGBoJ9MFF2Xj8=; b=HmyXfsI9Pe/+J8zgrd8Y2sOWrSTuZUWrcqk/O5qroUQU33ErVlE0JkHgu03sj7gLeU A9d/mbB4O++jrFFig9/opmNggnh9xaZPqb2rOciBwukuSx8dRE0cdblYz3sJR9MRYZ5C 5C9D3OX11H8WTj6Uqt4l0UUnvZDiRbFdsERTb4Mm8BEB1frdUdGQS6I1R7l8zjwAbKf4 JsPD728ycVHKQruKhCqc4jo66DbEzaTHwgqnGf9oOQo/YFGZVKJbgmE9YS0yY8TyAQJ4 VVmXh2SwS8/kpPjPkyFiFhPb/y4RzbB0aKhFycbKaRj9San02vMXYCG8v437qIMGG9Ls L+OA== 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=oAc0syotsHDUnWyUjFLewhBpFhavjrYGBoJ9MFF2Xj8=; b=g1sT445W+8FKOCspa1Z1KNHIXCJInLbB4giaD4MaCv83RyxNc8l9rJ+ElhMKMPP6LS 8/zTLjuNkqJ/TKl2RaX7ArpbD4aMTRqqv2kb3WVEQ+YhKQ5ciCPG8SHUNnKv9n/B7wjV TGIOT93KRVaS4Lod+ND/aEOteVhffWy8NTwSz3Bhk91JLQxSnbLDNa4B/QofFWvo452k whmEobc3QnY4CdM+eV7inHHPK30+bmnkvgznytOtXk+yXDhf6eAqnmGFiTh6MIoB849B HYwlg7AZ1Ususnkam1Fdowx8ZuT/IaTfOllZQpEF6DOz/zytJCUoQyHZAyNbaYtxgYur 6lEw== X-Gm-Message-State: AOAM533hEisD/dbLm2MT/w6ugQBpe2nlGobQW8t25N0rGyO+YvR5yrx2 4yKvfpAtLEmflKoNqd3+xRo= X-Google-Smtp-Source: ABdhPJyljXwJ37t6sHFLWWEoIcufoEF8yk5RrUa7RC6ngqeII3jL7f2C5zBR4UU6JQHTecUV/6rSIA== X-Received: by 2002:aa7:d0d7:: with SMTP id u23mr3735564edo.255.1616494792686; Tue, 23 Mar 2021 03:19:52 -0700 (PDT) Received: from localhost ([62.96.65.119]) by smtp.gmail.com with ESMTPSA id l12sm12506949edb.39.2021.03.23.03.19.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Mar 2021 03:19:48 -0700 (PDT) Date: Tue, 23 Mar 2021 11:20:08 +0100 From: Thierry Reding To: Dmitry Osipenko Cc: Mikko Perttunen , jonathanh@nvidia.com, airlied@linux.ie, daniel@ffwll.ch, linux-tegra@vger.kernel.org, dri-devel@lists.freedesktop.org, talho@nvidia.com, bhuntsman@nvidia.com Subject: Re: [PATCH v5 01/21] gpu: host1x: Use different lock classes for each client Message-ID: References: <20210111130019.3515669-1-mperttunen@nvidia.com> <20210111130019.3515669-2-mperttunen@nvidia.com> <6615105f-ccf1-7833-512c-090817c47952@gmail.com> <645366c2-c500-efcc-f44c-b933f6f470c4@nvidia.com> <6dec95ac-bd92-9434-76ba-eb7fcb316f49@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ycKTxQBNHbcJSd6i" Content-Disposition: inline In-Reply-To: <6dec95ac-bd92-9434-76ba-eb7fcb316f49@gmail.com> User-Agent: Mutt/2.0.6 (98f8cb83) (2021-03-06) Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org --ycKTxQBNHbcJSd6i Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 22, 2021 at 07:01:34PM +0300, Dmitry Osipenko wrote: > 22.03.2021 18:19, Mikko Perttunen =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > > On 22.3.2021 16.48, Dmitry Osipenko wrote: > >> 22.03.2021 17:46, Thierry Reding =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > >>> On Mon, Jan 11, 2021 at 02:59:59PM +0200, Mikko Perttunen wrote: > >>>> To avoid false lockdep warnings, give each client lock a different > >>>> lock class, passed from the initialization site by macro. > >>>> > >>>> Signed-off-by: Mikko Perttunen > >>>> --- > >>>> =C2=A0 drivers/gpu/host1x/bus.c | 7 ++++--- > >>>> =C2=A0 include/linux/host1x.h=C2=A0=C2=A0 | 9 ++++++++- > >>>> =C2=A0 2 files changed, 12 insertions(+), 4 deletions(-) > >>>> > >>>> diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c > >>>> index 347fb962b6c9..8fc79e9cb652 100644 > >>>> --- a/drivers/gpu/host1x/bus.c > >>>> +++ b/drivers/gpu/host1x/bus.c > >>>> @@ -715,13 +715,14 @@ EXPORT_SYMBOL(host1x_driver_unregister); > >>>> =C2=A0=C2=A0 * device and call host1x_device_init(), which will in t= urn call > >>>> each client's > >>>> =C2=A0=C2=A0 * &host1x_client_ops.init implementation. > >>>> =C2=A0=C2=A0 */ > >>>> -int host1x_client_register(struct host1x_client *client) > >>>> +int __host1x_client_register(struct host1x_client *client, > >>>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0 struct lock_class_key *key) > >>> > >>> I've seen the kbuild robot warn about this because the kerneldoc is n= ow > >>> out of date. > >>> > >>>> =C2=A0 { > >>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 struct host1x *host1x; > >>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 int err; > >>>> =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 INIT_LIST_HEAD(&client->list); > >>>> -=C2=A0=C2=A0=C2=A0 mutex_init(&client->lock); > >>>> +=C2=A0=C2=A0=C2=A0 __mutex_init(&client->lock, "host1x client lock"= , key); > >>> > >>> Should we maybe attempt to make this unique? Could we use something l= ike > >>> dev_name(client->dev) for this? > >> > >> I'm curious who the lockdep warning could be triggered at all, I don't > >> recall ever seeing it. Mikko, could you please clarify how to reproduce > >> the warning? > >> > >=20 > > This is pretty difficult to read but I guess it's some interaction > > related to the delayed initialization of host1x clients? In any case, I > > consistently get it at boot (though it may be triggered by vic probe > > instead of nvdec). > >=20 > > I'll fix the kbuild robot warnings and see if I can add a > > client-specific lock name for v6. >=20 > Thank you for the clarification! We now actually have a similar problem o= n Tegra20 after fixing the coupling of display controllers using the dc1_cl= ient->parent=3Ddc0_client and I see the same warning when DC1 is enabled. >=20 > [ 3.808338] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > [ 3.808355] WARNING: possible recursive locking detected > [ 3.808376] 5.12.0-rc3-next-20210319-00176-g60867e51e180 #7219 Tainted= : G W =20 > [ 3.808406] -------------------------------------------- > [ 3.808421] kworker/1:2/108 is trying to acquire lock: > [ 3.808449] c36b70a4 (&client->lock){+.+.}-{3:3}, at: host1x_client_re= sume+0x17/0x58 > [ 3.808586]=20 > but task is already holding lock: > [ 3.808603] c34df8a4 (&client->lock){+.+.}-{3:3}, at: host1x_client_re= sume+0x17/0x58 > [ 3.808712]=20 > other info that might help us debug this: > [ 3.808729] Possible unsafe locking scenario: >=20 > [ 3.808744] CPU0 > [ 3.808757] ---- > [ 3.808771] lock(&client->lock); > [ 3.808810] lock(&client->lock); > [ 3.808821]=20 > *** DEADLOCK *** >=20 > [ 3.808825] May be due to missing lock nesting notation >=20 > [ 3.808829] 15 locks held by kworker/1:2/108: > [ 3.808836] #0: c20068a8 ((wq_completion)events){+.+.}-{0:0}, at: pro= cess_one_work+0x15a/0x608 > [ 3.808878] #1: c2bbbf18 (deferred_probe_work){+.+.}-{0:0}, at: proce= ss_one_work+0x15a/0x608 > [ 3.808912] #2: c366d4d8 (&dev->mutex){....}-{3:3}, at: __device_atta= ch+0x29/0xdc > [ 3.808953] #3: c141a980 (devices_lock){+.+.}-{3:3}, at: host1x_clien= t_register+0x35/0xfc > [ 3.808986] #4: c34df64c (&host1x->devices_lock){+.+.}-{3:3}, at: hos= t1x_client_register+0x51/0xfc > [ 3.809017] #5: c34ed4d8 (&dev->mutex){....}-{3:3}, at: __device_atta= ch+0x29/0xdc > [ 3.809050] #6: c13faf5c (registration_lock){+.+.}-{3:3}, at: registe= r_framebuffer+0x2d/0x274 > [ 3.809092] #7: c132566c (console_lock){+.+.}-{0:0}, at: register_fra= mebuffer+0x219/0x274 > [ 3.809124] #8: c36e7848 (&fb_info->lock){+.+.}-{3:3}, at: register_f= ramebuffer+0x19f/0x274 > [ 3.809157] #9: c36d2d6c (&helper->lock){+.+.}-{3:3}, at: __drm_fb_he= lper_restore_fbdev_mode_unlocked+0x41/0x8c > [ 3.809199] #10: c36f00e8 (&dev->master_mutex){+.+.}-{3:3}, at: drm_m= aster_internal_acquire+0x17/0x28 > [ 3.809233] #11: c36d2c50 (&client->modeset_mutex){+.+.}-{3:3}, at: d= rm_client_modeset_commit_locked+0x1d/0x138 > [ 3.809272] #12: c2bbba28 (crtc_ww_class_acquire){+.+.}-{0:0}, at: dr= m_client_modeset_commit_atomic+0x2f/0x1c4 > [ 3.809306] #13: c36e6448 (crtc_ww_class_mutex){+.+.}-{3:3}, at: drm_= modeset_backoff+0x63/0x190 > [ 3.809337] #14: c34df8a4 (&client->lock){+.+.}-{3:3}, at: host1x_cli= ent_resume+0x17/0x58 > [ 3.809369]=20 > stack backtrace: > [ 3.809375] CPU: 1 PID: 108 Comm: kworker/1:2 Tainted: G W = 5.12.0-rc3-next-20210319-00176-g60867e51e180 #7219 > [ 3.809387] Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) > [ 3.809396] Workqueue: events deferred_probe_work_func > [ 3.809417] [] (unwind_backtrace) from [] (show_st= ack+0x11/0x14) > [ 3.809447] [] (show_stack) from [] (dump_stack+0x= 9f/0xb8) > [ 3.809467] [] (dump_stack) from [] (__lock_acquir= e+0x7fb/0x253c) > [ 3.809495] [] (__lock_acquire) from [] (lock_acqu= ire+0xf3/0x420) > [ 3.809516] [] (lock_acquire) from [] (__mutex_loc= k+0x87/0x814) > [ 3.809544] [] (__mutex_lock) from [] (mutex_lock_= nested+0x19/0x20) > [ 3.809565] [] (mutex_lock_nested) from [] (host1x= _client_resume+0x17/0x58) > [ 3.809587] [] (host1x_client_resume) from [] (hos= t1x_client_resume+0x1f/0x58) > [ 3.809604] [] (host1x_client_resume) from [] (teg= ra_crtc_atomic_enable+0x33/0x21c4) > [ 3.809634] [] (tegra_crtc_atomic_enable) from [] = (drm_atomic_helper_commit_modeset_enables+0x131/0x16c) > [ 3.809667] [] (drm_atomic_helper_commit_modeset_enables) fr= om [] (drm_atomic_helper_commit_tail_rpm+0x1d/0x4c) > [ 3.809691] [] (drm_atomic_helper_commit_tail_rpm) from [] (tegra_atomic_commit_tail+0x83/0x84) > [ 3.809712] [] (tegra_atomic_commit_tail) from [] = (commit_tail+0x71/0x138) > [ 3.809732] [] (commit_tail) from [] (drm_atomic_h= elper_commit+0xf1/0x114) > [ 3.809753] [] (drm_atomic_helper_commit) from [] = (drm_client_modeset_commit_atomic+0x199/0x1c4) > [ 3.809777] [] (drm_client_modeset_commit_atomic) from [] (drm_client_modeset_commit_locked+0x3d/0x138) > [ 3.809798] [] (drm_client_modeset_commit_locked) from [] (drm_client_modeset_commit+0x1b/0x2c) > [ 3.809818] [] (drm_client_modeset_commit) from []= (__drm_fb_helper_restore_fbdev_mode_unlocked+0x73/0x8c) > [ 3.809842] [] (__drm_fb_helper_restore_fbdev_mode_unlocked)= from [] (drm_fb_helper_set_par+0x2d/0x4c) > [ 3.809862] [] (drm_fb_helper_set_par) from [] (fb= con_init+0x1cb/0x370) > [ 3.809883] [] (fbcon_init) from [] (visual_init+0= x8b/0xc8) > [ 3.809902] [] (visual_init) from [] (do_bind_con_= driver+0x13d/0x2b4) > [ 3.809919] [] (do_bind_con_driver) from [] (do_ta= ke_over_console+0xdf/0x15c) > [ 3.809937] [] (do_take_over_console) from [] (do_= fbcon_takeover+0x4f/0x90) > [ 3.809955] [] (do_fbcon_takeover) from [] (regist= er_framebuffer+0x1a5/0x274) > [ 3.809977] [] (register_framebuffer) from [] (__d= rm_fb_helper_initial_config_and_unlock+0x29f/0x438) > [ 3.809999] [] (__drm_fb_helper_initial_config_and_unlock) f= rom [] (tegra_drm_fb_init+0x25/0x5c) > [ 3.810022] [] (tegra_drm_fb_init) from [] (host1x= _drm_probe+0x247/0x404) > [ 3.810041] [] (host1x_drm_probe) from [] (really_= probe+0xb1/0x2a4) > [ 3.810064] [] (really_probe) from [] (driver_prob= e_device+0x3f/0x78) > [ 3.810086] [] (driver_probe_device) from [] (bus_= for_each_drv+0x4f/0x78) > [ 3.810107] [] (bus_for_each_drv) from [] (__devic= e_attach+0x95/0xdc) > [ 3.810127] [] (__device_attach) from [] (bus_prob= e_device+0x5d/0x64) > [ 3.810147] [] (bus_probe_device) from [] (device_= add+0x293/0x5c0) > [ 3.810166] [] (device_add) from [] (host1x_subdev= _register+0x8d/0xac) > [ 3.810186] [] (host1x_subdev_register) from [] (h= ost1x_client_register+0x8f/0xfc) > [ 3.810204] [] (host1x_client_register) from [] (t= egra_dc_probe+0x1bf/0x2b0) > [ 3.810225] [] (tegra_dc_probe) from [] (platform_= probe+0x43/0x80) > [ 3.810247] [] (platform_probe) from [] (really_pr= obe+0xb1/0x2a4) > [ 3.810266] [] (really_probe) from [] (driver_prob= e_device+0x3f/0x78) > [ 3.810286] [] (driver_probe_device) from [] (bus_= for_each_drv+0x4f/0x78) > [ 3.810307] [] (bus_for_each_drv) from [] (__devic= e_attach+0x95/0xdc) > [ 3.810326] [] (__device_attach) from [] (bus_prob= e_device+0x5d/0x64) > [ 3.810346] [] (bus_probe_device) from [] (deferre= d_probe_work_func+0x4d/0x70) > [ 3.810367] [] (deferred_probe_work_func) from [] = (process_one_work+0x1eb/0x608) > [ 3.810391] [] (process_one_work) from [] (worker_= thread+0xf9/0x3bc) > [ 3.810411] [] (worker_thread) from [] (kthread+0x= ff/0x134) > [ 3.810432] [] (kthread) from [] (ret_from_fork+0x= 11/0x38) > [ 3.810449] Exception stack(0xc2bbbfb0 to 0xc2bbbff8) Sounds like we should decouple this from the series and fast-track this for v5.13, or perhaps even v5.12 along with the DC coupling fix? Thierry --ycKTxQBNHbcJSd6i Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAmBZwNgACgkQ3SOs138+ s6HTehAAu4QEPwwJFoucJfdb9SOeCGRCRTfDM9fuM07fYsaR6d87aISrA/UwNPy5 Louk0D73zp4Lb6QPSGNkCW11Gd/QCOuzHnbiQOu+NlWhHGYSQVw5DDYJihdPuTYZ OYP0SKdQB7XnVC6rQwIEvf968stj/zi/HlmWf68Js4PoFg7j4ZEEAnJIT7Z0Dyay bRDQdG09kpvt9ZLDOFHgcEz9eC9obCTHnOFawu30Mu4vts94RitKEA+cdb9w7Zpv QCE7qS/9xwJhIoMFOmhIkAqp05gFiL8EqYxNtWXEVsc7s0BZ/1k+tKxoZKBcqEF1 8W8neTvyYnOb54MoouWtnM1A8K6VoeAJgXZCGN/YSKQiXLdB4ZCIRJbzFd9QPpHK 5bUJHWpL3Gru+qulkqXENDZ2i4exvvHKjVKffAFzqjOzHq3mw5T5Q2RUx9L4CAn0 MYosz5DAzwOKeyZly0bmWAH5sOw7ItUcsno+rFoPtBpOvXct6UtG407SxgE40HmU C/nPT040DB/sN78MT2L+XRZIe2d9lUexvAmyh6CE9TvDTdbeYJrZjqGvhQZHSqO7 HH1/QLqEuMqvkkeQUnghaQ2QvqRe2ymgiVExtETevJNsl8Q5tXKckPp1U4t444eR eRGgekZVs54LExt70DDlhkhGdCj3NZ6GBEcJG2vpwi47h7X99YE= =miAu -----END PGP SIGNATURE----- --ycKTxQBNHbcJSd6i-- 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=-12.0 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AD926C433DB for ; Tue, 23 Mar 2021 10:19:55 +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 4CAA5619AE for ; Tue, 23 Mar 2021 10:19:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4CAA5619AE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C4D966E88B; Tue, 23 Mar 2021 10:19:54 +0000 (UTC) Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by gabe.freedesktop.org (Postfix) with ESMTPS id 189CE6E88B for ; Tue, 23 Mar 2021 10:19:54 +0000 (UTC) Received: by mail-ed1-x52f.google.com with SMTP id h13so22789843eds.5 for ; Tue, 23 Mar 2021 03:19:54 -0700 (PDT) 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=oAc0syotsHDUnWyUjFLewhBpFhavjrYGBoJ9MFF2Xj8=; b=HmyXfsI9Pe/+J8zgrd8Y2sOWrSTuZUWrcqk/O5qroUQU33ErVlE0JkHgu03sj7gLeU A9d/mbB4O++jrFFig9/opmNggnh9xaZPqb2rOciBwukuSx8dRE0cdblYz3sJR9MRYZ5C 5C9D3OX11H8WTj6Uqt4l0UUnvZDiRbFdsERTb4Mm8BEB1frdUdGQS6I1R7l8zjwAbKf4 JsPD728ycVHKQruKhCqc4jo66DbEzaTHwgqnGf9oOQo/YFGZVKJbgmE9YS0yY8TyAQJ4 VVmXh2SwS8/kpPjPkyFiFhPb/y4RzbB0aKhFycbKaRj9San02vMXYCG8v437qIMGG9Ls L+OA== 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=oAc0syotsHDUnWyUjFLewhBpFhavjrYGBoJ9MFF2Xj8=; b=PmEQOyh8MF4Ci0QNnT5EvKxW/cXh9SzOtLczKLhoK4UULZXA69zjrbvh1i/sW7AosU veNTrSpENAsnLy4QNqMmCm25NZyn6p/IZGH7AxqKC6AwPmkHPLHr/lzjPtUa77gldXV8 wufKMhZeM86dIj/ycwcRZ+bSJ4MujJEBKlOm/ZQzP5SQS1ig/NQDWN9vRPTqRMhdcMt8 +BIIfjR9mGMHsOUuXa8HzdflYr9McwSStQtCXqkQgqvN2tYLhS0jf/PcUeU4iPVVtPxn D7WF6vsd70Bhk2NXavkXvtKmr50v3bPC8MYG82yYNQJLBZwuOKihM3yiN+eTVExykuYe nwjw== X-Gm-Message-State: AOAM533nxQq936qUD+FrQLq4LXvcegjFAUkrCnpIamTj8OSecysP8PuR ppiCblk0lGXgnWu+0mLwGgUCTyt068I= X-Google-Smtp-Source: ABdhPJyljXwJ37t6sHFLWWEoIcufoEF8yk5RrUa7RC6ngqeII3jL7f2C5zBR4UU6JQHTecUV/6rSIA== X-Received: by 2002:aa7:d0d7:: with SMTP id u23mr3735564edo.255.1616494792686; Tue, 23 Mar 2021 03:19:52 -0700 (PDT) Received: from localhost ([62.96.65.119]) by smtp.gmail.com with ESMTPSA id l12sm12506949edb.39.2021.03.23.03.19.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Mar 2021 03:19:48 -0700 (PDT) Date: Tue, 23 Mar 2021 11:20:08 +0100 From: Thierry Reding To: Dmitry Osipenko Subject: Re: [PATCH v5 01/21] gpu: host1x: Use different lock classes for each client Message-ID: References: <20210111130019.3515669-1-mperttunen@nvidia.com> <20210111130019.3515669-2-mperttunen@nvidia.com> <6615105f-ccf1-7833-512c-090817c47952@gmail.com> <645366c2-c500-efcc-f44c-b933f6f470c4@nvidia.com> <6dec95ac-bd92-9434-76ba-eb7fcb316f49@gmail.com> MIME-Version: 1.0 In-Reply-To: <6dec95ac-bd92-9434-76ba-eb7fcb316f49@gmail.com> User-Agent: Mutt/2.0.6 (98f8cb83) (2021-03-06) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: airlied@linux.ie, dri-devel@lists.freedesktop.org, jonathanh@nvidia.com, talho@nvidia.com, bhuntsman@nvidia.com, linux-tegra@vger.kernel.org, Mikko Perttunen Content-Type: multipart/mixed; boundary="===============0894113103==" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --===============0894113103== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ycKTxQBNHbcJSd6i" Content-Disposition: inline --ycKTxQBNHbcJSd6i Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 22, 2021 at 07:01:34PM +0300, Dmitry Osipenko wrote: > 22.03.2021 18:19, Mikko Perttunen =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > > On 22.3.2021 16.48, Dmitry Osipenko wrote: > >> 22.03.2021 17:46, Thierry Reding =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > >>> On Mon, Jan 11, 2021 at 02:59:59PM +0200, Mikko Perttunen wrote: > >>>> To avoid false lockdep warnings, give each client lock a different > >>>> lock class, passed from the initialization site by macro. > >>>> > >>>> Signed-off-by: Mikko Perttunen > >>>> --- > >>>> =C2=A0 drivers/gpu/host1x/bus.c | 7 ++++--- > >>>> =C2=A0 include/linux/host1x.h=C2=A0=C2=A0 | 9 ++++++++- > >>>> =C2=A0 2 files changed, 12 insertions(+), 4 deletions(-) > >>>> > >>>> diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c > >>>> index 347fb962b6c9..8fc79e9cb652 100644 > >>>> --- a/drivers/gpu/host1x/bus.c > >>>> +++ b/drivers/gpu/host1x/bus.c > >>>> @@ -715,13 +715,14 @@ EXPORT_SYMBOL(host1x_driver_unregister); > >>>> =C2=A0=C2=A0 * device and call host1x_device_init(), which will in t= urn call > >>>> each client's > >>>> =C2=A0=C2=A0 * &host1x_client_ops.init implementation. > >>>> =C2=A0=C2=A0 */ > >>>> -int host1x_client_register(struct host1x_client *client) > >>>> +int __host1x_client_register(struct host1x_client *client, > >>>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0 struct lock_class_key *key) > >>> > >>> I've seen the kbuild robot warn about this because the kerneldoc is n= ow > >>> out of date. > >>> > >>>> =C2=A0 { > >>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 struct host1x *host1x; > >>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 int err; > >>>> =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 INIT_LIST_HEAD(&client->list); > >>>> -=C2=A0=C2=A0=C2=A0 mutex_init(&client->lock); > >>>> +=C2=A0=C2=A0=C2=A0 __mutex_init(&client->lock, "host1x client lock"= , key); > >>> > >>> Should we maybe attempt to make this unique? Could we use something l= ike > >>> dev_name(client->dev) for this? > >> > >> I'm curious who the lockdep warning could be triggered at all, I don't > >> recall ever seeing it. Mikko, could you please clarify how to reproduce > >> the warning? > >> > >=20 > > This is pretty difficult to read but I guess it's some interaction > > related to the delayed initialization of host1x clients? In any case, I > > consistently get it at boot (though it may be triggered by vic probe > > instead of nvdec). > >=20 > > I'll fix the kbuild robot warnings and see if I can add a > > client-specific lock name for v6. >=20 > Thank you for the clarification! We now actually have a similar problem o= n Tegra20 after fixing the coupling of display controllers using the dc1_cl= ient->parent=3Ddc0_client and I see the same warning when DC1 is enabled. >=20 > [ 3.808338] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > [ 3.808355] WARNING: possible recursive locking detected > [ 3.808376] 5.12.0-rc3-next-20210319-00176-g60867e51e180 #7219 Tainted= : G W =20 > [ 3.808406] -------------------------------------------- > [ 3.808421] kworker/1:2/108 is trying to acquire lock: > [ 3.808449] c36b70a4 (&client->lock){+.+.}-{3:3}, at: host1x_client_re= sume+0x17/0x58 > [ 3.808586]=20 > but task is already holding lock: > [ 3.808603] c34df8a4 (&client->lock){+.+.}-{3:3}, at: host1x_client_re= sume+0x17/0x58 > [ 3.808712]=20 > other info that might help us debug this: > [ 3.808729] Possible unsafe locking scenario: >=20 > [ 3.808744] CPU0 > [ 3.808757] ---- > [ 3.808771] lock(&client->lock); > [ 3.808810] lock(&client->lock); > [ 3.808821]=20 > *** DEADLOCK *** >=20 > [ 3.808825] May be due to missing lock nesting notation >=20 > [ 3.808829] 15 locks held by kworker/1:2/108: > [ 3.808836] #0: c20068a8 ((wq_completion)events){+.+.}-{0:0}, at: pro= cess_one_work+0x15a/0x608 > [ 3.808878] #1: c2bbbf18 (deferred_probe_work){+.+.}-{0:0}, at: proce= ss_one_work+0x15a/0x608 > [ 3.808912] #2: c366d4d8 (&dev->mutex){....}-{3:3}, at: __device_atta= ch+0x29/0xdc > [ 3.808953] #3: c141a980 (devices_lock){+.+.}-{3:3}, at: host1x_clien= t_register+0x35/0xfc > [ 3.808986] #4: c34df64c (&host1x->devices_lock){+.+.}-{3:3}, at: hos= t1x_client_register+0x51/0xfc > [ 3.809017] #5: c34ed4d8 (&dev->mutex){....}-{3:3}, at: __device_atta= ch+0x29/0xdc > [ 3.809050] #6: c13faf5c (registration_lock){+.+.}-{3:3}, at: registe= r_framebuffer+0x2d/0x274 > [ 3.809092] #7: c132566c (console_lock){+.+.}-{0:0}, at: register_fra= mebuffer+0x219/0x274 > [ 3.809124] #8: c36e7848 (&fb_info->lock){+.+.}-{3:3}, at: register_f= ramebuffer+0x19f/0x274 > [ 3.809157] #9: c36d2d6c (&helper->lock){+.+.}-{3:3}, at: __drm_fb_he= lper_restore_fbdev_mode_unlocked+0x41/0x8c > [ 3.809199] #10: c36f00e8 (&dev->master_mutex){+.+.}-{3:3}, at: drm_m= aster_internal_acquire+0x17/0x28 > [ 3.809233] #11: c36d2c50 (&client->modeset_mutex){+.+.}-{3:3}, at: d= rm_client_modeset_commit_locked+0x1d/0x138 > [ 3.809272] #12: c2bbba28 (crtc_ww_class_acquire){+.+.}-{0:0}, at: dr= m_client_modeset_commit_atomic+0x2f/0x1c4 > [ 3.809306] #13: c36e6448 (crtc_ww_class_mutex){+.+.}-{3:3}, at: drm_= modeset_backoff+0x63/0x190 > [ 3.809337] #14: c34df8a4 (&client->lock){+.+.}-{3:3}, at: host1x_cli= ent_resume+0x17/0x58 > [ 3.809369]=20 > stack backtrace: > [ 3.809375] CPU: 1 PID: 108 Comm: kworker/1:2 Tainted: G W = 5.12.0-rc3-next-20210319-00176-g60867e51e180 #7219 > [ 3.809387] Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) > [ 3.809396] Workqueue: events deferred_probe_work_func > [ 3.809417] [] (unwind_backtrace) from [] (show_st= ack+0x11/0x14) > [ 3.809447] [] (show_stack) from [] (dump_stack+0x= 9f/0xb8) > [ 3.809467] [] (dump_stack) from [] (__lock_acquir= e+0x7fb/0x253c) > [ 3.809495] [] (__lock_acquire) from [] (lock_acqu= ire+0xf3/0x420) > [ 3.809516] [] (lock_acquire) from [] (__mutex_loc= k+0x87/0x814) > [ 3.809544] [] (__mutex_lock) from [] (mutex_lock_= nested+0x19/0x20) > [ 3.809565] [] (mutex_lock_nested) from [] (host1x= _client_resume+0x17/0x58) > [ 3.809587] [] (host1x_client_resume) from [] (hos= t1x_client_resume+0x1f/0x58) > [ 3.809604] [] (host1x_client_resume) from [] (teg= ra_crtc_atomic_enable+0x33/0x21c4) > [ 3.809634] [] (tegra_crtc_atomic_enable) from [] = (drm_atomic_helper_commit_modeset_enables+0x131/0x16c) > [ 3.809667] [] (drm_atomic_helper_commit_modeset_enables) fr= om [] (drm_atomic_helper_commit_tail_rpm+0x1d/0x4c) > [ 3.809691] [] (drm_atomic_helper_commit_tail_rpm) from [] (tegra_atomic_commit_tail+0x83/0x84) > [ 3.809712] [] (tegra_atomic_commit_tail) from [] = (commit_tail+0x71/0x138) > [ 3.809732] [] (commit_tail) from [] (drm_atomic_h= elper_commit+0xf1/0x114) > [ 3.809753] [] (drm_atomic_helper_commit) from [] = (drm_client_modeset_commit_atomic+0x199/0x1c4) > [ 3.809777] [] (drm_client_modeset_commit_atomic) from [] (drm_client_modeset_commit_locked+0x3d/0x138) > [ 3.809798] [] (drm_client_modeset_commit_locked) from [] (drm_client_modeset_commit+0x1b/0x2c) > [ 3.809818] [] (drm_client_modeset_commit) from []= (__drm_fb_helper_restore_fbdev_mode_unlocked+0x73/0x8c) > [ 3.809842] [] (__drm_fb_helper_restore_fbdev_mode_unlocked)= from [] (drm_fb_helper_set_par+0x2d/0x4c) > [ 3.809862] [] (drm_fb_helper_set_par) from [] (fb= con_init+0x1cb/0x370) > [ 3.809883] [] (fbcon_init) from [] (visual_init+0= x8b/0xc8) > [ 3.809902] [] (visual_init) from [] (do_bind_con_= driver+0x13d/0x2b4) > [ 3.809919] [] (do_bind_con_driver) from [] (do_ta= ke_over_console+0xdf/0x15c) > [ 3.809937] [] (do_take_over_console) from [] (do_= fbcon_takeover+0x4f/0x90) > [ 3.809955] [] (do_fbcon_takeover) from [] (regist= er_framebuffer+0x1a5/0x274) > [ 3.809977] [] (register_framebuffer) from [] (__d= rm_fb_helper_initial_config_and_unlock+0x29f/0x438) > [ 3.809999] [] (__drm_fb_helper_initial_config_and_unlock) f= rom [] (tegra_drm_fb_init+0x25/0x5c) > [ 3.810022] [] (tegra_drm_fb_init) from [] (host1x= _drm_probe+0x247/0x404) > [ 3.810041] [] (host1x_drm_probe) from [] (really_= probe+0xb1/0x2a4) > [ 3.810064] [] (really_probe) from [] (driver_prob= e_device+0x3f/0x78) > [ 3.810086] [] (driver_probe_device) from [] (bus_= for_each_drv+0x4f/0x78) > [ 3.810107] [] (bus_for_each_drv) from [] (__devic= e_attach+0x95/0xdc) > [ 3.810127] [] (__device_attach) from [] (bus_prob= e_device+0x5d/0x64) > [ 3.810147] [] (bus_probe_device) from [] (device_= add+0x293/0x5c0) > [ 3.810166] [] (device_add) from [] (host1x_subdev= _register+0x8d/0xac) > [ 3.810186] [] (host1x_subdev_register) from [] (h= ost1x_client_register+0x8f/0xfc) > [ 3.810204] [] (host1x_client_register) from [] (t= egra_dc_probe+0x1bf/0x2b0) > [ 3.810225] [] (tegra_dc_probe) from [] (platform_= probe+0x43/0x80) > [ 3.810247] [] (platform_probe) from [] (really_pr= obe+0xb1/0x2a4) > [ 3.810266] [] (really_probe) from [] (driver_prob= e_device+0x3f/0x78) > [ 3.810286] [] (driver_probe_device) from [] (bus_= for_each_drv+0x4f/0x78) > [ 3.810307] [] (bus_for_each_drv) from [] (__devic= e_attach+0x95/0xdc) > [ 3.810326] [] (__device_attach) from [] (bus_prob= e_device+0x5d/0x64) > [ 3.810346] [] (bus_probe_device) from [] (deferre= d_probe_work_func+0x4d/0x70) > [ 3.810367] [] (deferred_probe_work_func) from [] = (process_one_work+0x1eb/0x608) > [ 3.810391] [] (process_one_work) from [] (worker_= thread+0xf9/0x3bc) > [ 3.810411] [] (worker_thread) from [] (kthread+0x= ff/0x134) > [ 3.810432] [] (kthread) from [] (ret_from_fork+0x= 11/0x38) > [ 3.810449] Exception stack(0xc2bbbfb0 to 0xc2bbbff8) Sounds like we should decouple this from the series and fast-track this for v5.13, or perhaps even v5.12 along with the DC coupling fix? Thierry --ycKTxQBNHbcJSd6i Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAmBZwNgACgkQ3SOs138+ s6HTehAAu4QEPwwJFoucJfdb9SOeCGRCRTfDM9fuM07fYsaR6d87aISrA/UwNPy5 Louk0D73zp4Lb6QPSGNkCW11Gd/QCOuzHnbiQOu+NlWhHGYSQVw5DDYJihdPuTYZ OYP0SKdQB7XnVC6rQwIEvf968stj/zi/HlmWf68Js4PoFg7j4ZEEAnJIT7Z0Dyay bRDQdG09kpvt9ZLDOFHgcEz9eC9obCTHnOFawu30Mu4vts94RitKEA+cdb9w7Zpv QCE7qS/9xwJhIoMFOmhIkAqp05gFiL8EqYxNtWXEVsc7s0BZ/1k+tKxoZKBcqEF1 8W8neTvyYnOb54MoouWtnM1A8K6VoeAJgXZCGN/YSKQiXLdB4ZCIRJbzFd9QPpHK 5bUJHWpL3Gru+qulkqXENDZ2i4exvvHKjVKffAFzqjOzHq3mw5T5Q2RUx9L4CAn0 MYosz5DAzwOKeyZly0bmWAH5sOw7ItUcsno+rFoPtBpOvXct6UtG407SxgE40HmU C/nPT040DB/sN78MT2L+XRZIe2d9lUexvAmyh6CE9TvDTdbeYJrZjqGvhQZHSqO7 HH1/QLqEuMqvkkeQUnghaQ2QvqRe2ymgiVExtETevJNsl8Q5tXKckPp1U4t444eR eRGgekZVs54LExt70DDlhkhGdCj3NZ6GBEcJG2vpwi47h7X99YE= =miAu -----END PGP SIGNATURE----- --ycKTxQBNHbcJSd6i-- --===============0894113103== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel --===============0894113103==--