From nobody Thu Apr 16 00:40:36 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36583C4332F for ; Wed, 23 Nov 2022 00:14:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235173AbiKWAOT (ORCPT ); Tue, 22 Nov 2022 19:14:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234681AbiKWAOQ (ORCPT ); Tue, 22 Nov 2022 19:14:16 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C291AD328D for ; Tue, 22 Nov 2022 16:14:15 -0800 (PST) Received: from dimapc.. (109-252-117-140.nat.spd-mgts.ru [109.252.117.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 1F6476602A9F; Wed, 23 Nov 2022 00:14:13 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1669162453; bh=CjfoupBANitx/AKoGxyh1s9D/gZeN1CU4qbRETlE+4k=; h=From:To:Cc:Subject:Date:From; b=bhGlGP4QmVJocJpVlT6d0e2EYlzQqO/gsofScbdgqWtPDF2iNG4Uixj2pqveUT30I JzwkZS6f/BDgfPUpCTh7G/MuMvUwjkZOyjmBgCl3sn1vlM3xc7MkvHB1SgPB4AFXNU 4h4Zl3+2BsaLdnxuG3UGBiFcm0Czjd2DIyeSqLCQz1BrQYQ3+IwxtSz4fT3WD2Jqi5 VdaEhEEZz16wMZkkuiNySwo9KmSByjNzSg8DyJJZpLBXwY1UEO+UDDMAPcLKydSqxa vjGNj9lkh5YdzNydlQloq5Ti3ho3Kh5uqh3hU/vEauyhDm5wGYEAIxgKnoVe6HSyv5 VEGTqZnRH7Kkg== From: Dmitry Osipenko To: Luben Tuikov , =?UTF-8?q?Christian=20K=C3=B6nig?= , David Airlie , Daniel Vetter Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v1] drm/scheduler: Fix lockup in drm_sched_entity_kill() Date: Wed, 23 Nov 2022 03:13:03 +0300 Message-Id: <20221123001303.533968-1-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The drm_sched_entity_kill() is invoked twice by drm_sched_entity_destroy() while userspace process is exiting or being killed. First time it's invoked when sched entity is flushed and second time when entity is released. This causes a lockup within wait_for_completion(entity_idle) due to how completi= on API works. Calling wait_for_completion() more times than complete() was invoked is a error condition that causes lockup because completion internally uses counter for complete/wait calls. The complete_all() must be used instead in such cases. This patch fixes lockup of Panfrost driver that is reproducible by killing any application in a middle of 3d drawing operation. Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini") Signed-off-by: Dmitry Osipenko Tested-By: Guilherme G. Piccoli # Steam Deck --- drivers/gpu/drm/scheduler/sched_entity.c | 2 +- drivers/gpu/drm/scheduler/sched_main.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/sch= eduler/sched_entity.c index fe09e5be79bd..15d04a0ec623 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -81,7 +81,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, init_completion(&entity->entity_idle); =20 /* We start in an idle state. */ - complete(&entity->entity_idle); + complete_all(&entity->entity_idle); =20 spin_lock_init(&entity->rq_lock); spsc_queue_init(&entity->job_queue); diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/sched= uler/sched_main.c index 6ce04c2e90c0..857ec20be9e8 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -1026,7 +1026,7 @@ static int drm_sched_main(void *param) sched_job =3D drm_sched_entity_pop_job(entity); =20 if (!sched_job) { - complete(&entity->entity_idle); + complete_all(&entity->entity_idle); continue; } =20 @@ -1037,7 +1037,7 @@ static int drm_sched_main(void *param) =20 trace_drm_run_job(sched_job, entity); fence =3D sched->ops->run_job(sched_job); - complete(&entity->entity_idle); + complete_all(&entity->entity_idle); drm_sched_fence_scheduled(s_fence); =20 if (!IS_ERR_OR_NULL(fence)) { --=20 2.38.1