From patchwork Tue Sep 8 15:22:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 264126 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 1365AC2D0A7 for ; Tue, 8 Sep 2020 19:57:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C443F21D41 for ; Tue, 8 Sep 2020 19:57:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599595065; bh=1EUNTz1A1r0KvF51vxWoUiWimGOeA2XSyupkEDGyzRA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZKReaGs67JKtHQDrAgMv1YXRg+ZSMzfLtlIjhPi/tLId8bcNx9hc3e/wTPXXdd4+I t0tKxwaLH1mKZyuXY1n8KVyR6xoV0IVA9M2ThrIyw8ETgnhsXvErzDfUjwJeLgdGnD v6vCsMiF0fQcTIdkIxjmN5XH36wYVKKQffwFFKwE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732512AbgIHT5p (ORCPT ); Tue, 8 Sep 2020 15:57:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:58872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730552AbgIHPfu (ORCPT ); Tue, 8 Sep 2020 11:35:50 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3276E2256B; Tue, 8 Sep 2020 15:35:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599579308; bh=1EUNTz1A1r0KvF51vxWoUiWimGOeA2XSyupkEDGyzRA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mzR50uws6mQbvkYNxiI30E7yTbtIjjwu2w0aJ8iKCf6ZEBCKx0c78XLNtMgHLah/S GPzGoSL38gK5t4YKBmbT0j2nBpBVpZuZqVFyyEIYQcsXx2mIUVidHXvI0hCNWX7Zhm l1bQ15kLFQMfU9+zWy/4RWasW2ylVIpRkIDvkq1c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomi Valkeinen , Laurent Pinchart , Sasha Levin Subject: [PATCH 5.8 024/186] drm/omap: fix incorrect lock state Date: Tue, 8 Sep 2020 17:22:46 +0200 Message-Id: <20200908152242.827276905@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908152241.646390211@linuxfoundation.org> References: <20200908152241.646390211@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tomi Valkeinen [ Upstream commit 7fd5b25499bcec157dd4de9a713425efcf4571cd ] After commit 92cc68e35863c1c61c449efa2b2daef6e9926048 ("drm/vblank: Use spin_(un)lock_irq() in drm_crtc_vblank_on()") omapdrm locking is broken: WARNING: inconsistent lock state 5.8.0-rc2-00483-g92cc68e35863 #13 Tainted: G W -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. swapper/0/0 [HC1[1]:SC0[0]:HE0:SE1] takes: ea98222c (&dev->event_lock#2){?.+.}-{2:2}, at: drm_handle_vblank+0x4c/0x520 [drm] {HARDIRQ-ON-W} state was registered at: trace_hardirqs_on+0x9c/0x1ec _raw_spin_unlock_irq+0x20/0x58 omap_crtc_atomic_enable+0x54/0xa0 [omapdrm] drm_atomic_helper_commit_modeset_enables+0x218/0x270 [drm_kms_helper] omap_atomic_commit_tail+0x48/0xc4 [omapdrm] commit_tail+0x9c/0x190 [drm_kms_helper] drm_atomic_helper_commit+0x154/0x188 [drm_kms_helper] drm_client_modeset_commit_atomic+0x228/0x268 [drm] drm_client_modeset_commit_locked+0x60/0x1d0 [drm] drm_client_modeset_commit+0x24/0x40 [drm] drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa8 [drm_kms_helper] drm_fb_helper_set_par+0x2c/0x5c [drm_kms_helper] drm_fb_helper_hotplug_event.part.0+0xa0/0xbc [drm_kms_helper] drm_kms_helper_hotplug_event+0x24/0x30 [drm_kms_helper] output_poll_execute+0x1a8/0x1c0 [drm_kms_helper] process_one_work+0x268/0x800 worker_thread+0x30/0x4e0 kthread+0x164/0x190 ret_from_fork+0x14/0x20 The reason for this is that omapdrm calls drm_crtc_vblank_on() while holding event_lock taken with spin_lock_irq(). It is not clear why drm_crtc_vblank_on() and drm_crtc_vblank_get() are called while holding event_lock. I don't see any problem with moving those calls outside the lock, which is what this patch does. Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20200819103021.440288-1-tomi.valkeinen@ti.com Reviewed-by: Laurent Pinchart Signed-off-by: Sasha Levin --- drivers/gpu/drm/omapdrm/omap_crtc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c index 6d40914675dad..328a4a74f534e 100644 --- a/drivers/gpu/drm/omapdrm/omap_crtc.c +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c @@ -451,11 +451,12 @@ static void omap_crtc_atomic_enable(struct drm_crtc *crtc, if (omap_state->manually_updated) return; - spin_lock_irq(&crtc->dev->event_lock); drm_crtc_vblank_on(crtc); + ret = drm_crtc_vblank_get(crtc); WARN_ON(ret != 0); + spin_lock_irq(&crtc->dev->event_lock); omap_crtc_arm_event(crtc); spin_unlock_irq(&crtc->dev->event_lock); }