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=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 701A7C433E0 for ; Thu, 11 Feb 2021 22:42:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BFEA64E3D for ; Thu, 11 Feb 2021 22:42:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230080AbhBKWlu (ORCPT ); Thu, 11 Feb 2021 17:41:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229564AbhBKWlk (ORCPT ); Thu, 11 Feb 2021 17:41:40 -0500 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ABD20C061574 for ; Thu, 11 Feb 2021 14:41:00 -0800 (PST) Received: by mail-pg1-x534.google.com with SMTP id o7so4978245pgl.1 for ; Thu, 11 Feb 2021 14:41:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=B6yvPNRRNRl+hAEm+aAT4OMwWbagrM0k8oerqfFt/Fk=; b=YY4SkTg7rV4kPjQAkZOLvLicOXO6Y+7cVQ/0LiM1pIHZgGh1E3le3JNADcZA9QBqwD RAPUqPDgumgL705j+GvlBu0L6iJycVzgsFNx1q5EHNd9O1z54qA7fR078HEud6FvhRbc eqXDmistUlMI3PCbnvlRLq4NNrGQBymskySB8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=B6yvPNRRNRl+hAEm+aAT4OMwWbagrM0k8oerqfFt/Fk=; b=OI+Cf/apONmiU1SXwUX9ejZcP4C33ig32MrXhqalZ/zomBBO4z+aq7otI0uGoFmygc /x5waJXjElL2wI6prbmmSSEsrZ49wwgsHvSK0zv/KGdk4Dnz4M0JIFk1kJpvd2Nklvyf y0i5uiXnpdaDi1OgXVedbnaSYZOrJksWttBIXEMjq3rLS7f4zjRT8RKlMevGvvdsz5cA /ZSKvoNOfz0re6xSQS1+YyLiHj/SAkQ5Zy/pZ1hJRO1ZU4dlLDVa8AYTG11rrhFGby+M gC5RRnIsZ7UoNIuYwtC3YI9+RvB9Z1cputX0kVRkHbGIwPrZUjdkJCLZuFypBvwCyN3F k4ng== X-Gm-Message-State: AOAM530aM1/C73wYZsfqfRhmOEysXrMJ8RxXm20RMkHp7zVQZWew+wne 1uw2SeCxfLqjCiy0sKoN0GhKiE0gdIMGXQ== X-Google-Smtp-Source: ABdhPJzT0xSERmgIjPMidxbPCsmfbyLhZNGEakqTmas5KJF/Xma8ce2B7quh8a1ulXA9ffLJ4R3uZA== X-Received: by 2002:a62:8416:0:b029:1dd:9d4e:7002 with SMTP id k22-20020a6284160000b02901dd9d4e7002mr321648pfd.18.1613083260119; Thu, 11 Feb 2021 14:41:00 -0800 (PST) Received: from smtp.gmail.com ([2620:15c:202:201:f038:5688:cf3c:eca2]) by smtp.gmail.com with ESMTPSA id i67sm6675454pfc.153.2021.02.11.14.40.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Feb 2021 14:40:59 -0800 (PST) From: Stephen Boyd To: Rob Clark Cc: linux-kernel@vger.kernel.org, Sean Paul , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, Krishna Manikandan , Daniel Vetter Subject: [PATCH] drm/msm/kms: Use nested locking for crtc lock instead of custom classes Date: Thu, 11 Feb 2021 14:40:58 -0800 Message-Id: <20210211224058.2853809-1-swboyd@chromium.org> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org We don't need to make up custom lock classes here, we can simply use mutex_lock_nested() and pass in the index of the crtc to the locking APIs instead. This helps lockdep understand that these are really different locks while avoiding having to allocate custom lockdep classes. Cc: Krishna Manikandan Suggested-by: Daniel Vetter Fixes: b3d91800d9ac ("drm/msm: Fix race condition in msm driver with async layer updates") Signed-off-by: Stephen Boyd --- drivers/gpu/drm/msm/msm_atomic.c | 7 +++++-- drivers/gpu/drm/msm/msm_kms.h | 8 ++------ 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c index 6a326761dc4a..edcaccaa27e6 100644 --- a/drivers/gpu/drm/msm/msm_atomic.c +++ b/drivers/gpu/drm/msm/msm_atomic.c @@ -57,10 +57,13 @@ static void vblank_put(struct msm_kms *kms, unsigned crtc_mask) static void lock_crtcs(struct msm_kms *kms, unsigned int crtc_mask) { + int crtc_index; struct drm_crtc *crtc; - for_each_crtc_mask(kms->dev, crtc, crtc_mask) - mutex_lock(&kms->commit_lock[drm_crtc_index(crtc)]); + for_each_crtc_mask(kms->dev, crtc, crtc_mask) { + crtc_index = drm_crtc_index(crtc); + mutex_lock_nested(&kms->commit_lock[crtc_index], crtc_index); + } } static void unlock_crtcs(struct msm_kms *kms, unsigned int crtc_mask) diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h index 4735251a394d..d8151a89e163 100644 --- a/drivers/gpu/drm/msm/msm_kms.h +++ b/drivers/gpu/drm/msm/msm_kms.h @@ -157,7 +157,6 @@ struct msm_kms { * from the crtc's pending_timer close to end of the frame: */ struct mutex commit_lock[MAX_CRTCS]; - struct lock_class_key commit_lock_keys[MAX_CRTCS]; unsigned pending_crtc_mask; struct msm_pending_timer pending_timers[MAX_CRTCS]; }; @@ -167,11 +166,8 @@ static inline int msm_kms_init(struct msm_kms *kms, { unsigned i, ret; - for (i = 0; i < ARRAY_SIZE(kms->commit_lock); i++) { - lockdep_register_key(&kms->commit_lock_keys[i]); - __mutex_init(&kms->commit_lock[i], "&kms->commit_lock[i]", - &kms->commit_lock_keys[i]); - } + for (i = 0; i < ARRAY_SIZE(kms->commit_lock); i++) + mutex_init(&kms->commit_lock[i]); kms->funcs = funcs; base-commit: 182b4a2d251305201b6f9cae29067f7112f05835 -- https://chromeos.dev