From nobody Fri Sep 5 20:02:06 2025 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 1B6F3C32792 for ; Tue, 23 Aug 2022 11:22:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242275AbiHWLVo (ORCPT ); Tue, 23 Aug 2022 07:21:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357480AbiHWLRh (ORCPT ); Tue, 23 Aug 2022 07:17:37 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45D5F89815; Tue, 23 Aug 2022 02:21:02 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D699F6121F; Tue, 23 Aug 2022 09:21:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3379C433C1; Tue, 23 Aug 2022 09:21:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661246461; bh=qthlUxLyneTrQoXxQBbYo31Gy/R5BpXEYmeBs7zGNCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mjbLSY6GQAexzQoMHeQxdizIjDbpO7E7jEibVek1qwzLlimCQWBRuJPAzla3q5gks ppNLkWOUZKVYc4xyz+FDZXKKGCY2F/L+ee3GYno3S/+SA2cjl/ZjO/gO+dS/PxkYtK 5zSPRuq1JFfpEBEVU+49xi+vjTDvnHVQ3GFrfVPE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rob Clark , Abhinav Kumar , Sasha Levin Subject: [PATCH 5.4 117/389] drm/msm/mdp5: Fix global state lock backoff Date: Tue, 23 Aug 2022 10:23:15 +0200 Message-Id: <20220823080120.501465746@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080115.331990024@linuxfoundation.org> References: <20220823080115.331990024@linuxfoundation.org> User-Agent: quilt/0.67 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" From: Rob Clark [ Upstream commit 92ef86ab513593c6329d04146e61f9a670e72fc5 ] We need to grab the lock after the early return for !hwpipe case. Otherwise, we could have hit contention yet still returned 0. Fixes an issue that the new CONFIG_DRM_DEBUG_MODESET_LOCK stuff flagged in CI: WARNING: CPU: 0 PID: 282 at drivers/gpu/drm/drm_modeset_lock.c:296 drm_m= odeset_lock+0xf8/0x154 Modules linked in: CPU: 0 PID: 282 Comm: kms_cursor_lega Tainted: G W 5.19.0= -rc2-15930-g875cc8bc536a #1 Hardware name: Qualcomm Technologies, Inc. DB820c (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=3D--) pc : drm_modeset_lock+0xf8/0x154 lr : drm_atomic_get_private_obj_state+0x84/0x170 sp : ffff80000cfab6a0 x29: ffff80000cfab6a0 x28: 0000000000000000 x27: ffff000083bc4d00 x26: 0000000000000038 x25: 0000000000000000 x24: ffff80000957ca58 x23: 0000000000000000 x22: ffff000081ace080 x21: 0000000000000001 x20: ffff000081acec18 x19: ffff80000cfabb80 x18: 0000000000000038 x17: 0000000000000000 x16: 0000000000000000 x15: fffffffffffea0d0 x14: 0000000000000000 x13: 284e4f5f4e524157 x12: 5f534b434f4c5f47 x11: ffff80000a386aa8 x10: 0000000000000029 x9 : ffff80000cfab610 x8 : 0000000000000029 x7 : 0000000000000014 x6 : 0000000000000000 x5 : 0000000000000001 x4 : ffff8000081ad904 x3 : 0000000000000029 x2 : ffff0000801db4c0 x1 : ffff80000cfabb80 x0 : ffff000081aceb58 Call trace: drm_modeset_lock+0xf8/0x154 drm_atomic_get_private_obj_state+0x84/0x170 mdp5_get_global_state+0x54/0x6c mdp5_pipe_release+0x2c/0xd4 mdp5_plane_atomic_check+0x2ec/0x414 drm_atomic_helper_check_planes+0xd8/0x210 drm_atomic_helper_check+0x54/0xb0 ... ---[ end trace 0000000000000000 ]--- drm_modeset_lock attempting to lock a contended lock without backoff: drm_modeset_lock+0x148/0x154 mdp5_get_global_state+0x30/0x6c mdp5_pipe_release+0x2c/0xd4 mdp5_plane_atomic_check+0x290/0x414 drm_atomic_helper_check_planes+0xd8/0x210 drm_atomic_helper_check+0x54/0xb0 drm_atomic_check_only+0x4b0/0x8f4 drm_atomic_commit+0x68/0xe0 Fixes: d59be579fa93 ("drm/msm/mdp5: Return error code in mdp5_pipe_release = when deadlock is detected") Signed-off-by: Rob Clark Reviewed-by: Abhinav Kumar Patchwork: https://patchwork.freedesktop.org/patch/492701/ Link: https://lore.kernel.org/r/20220707162040.1594855-1-robdclark@gmail.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/ms= m/disp/mdp5/mdp5_pipe.c index a4f5cb90f3e8..e4b8a789835a 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c @@ -123,12 +123,13 @@ int mdp5_pipe_release(struct drm_atomic_state *s, str= uct mdp5_hw_pipe *hwpipe) { struct msm_drm_private *priv =3D s->dev->dev_private; struct mdp5_kms *mdp5_kms =3D to_mdp5_kms(to_mdp_kms(priv->kms)); - struct mdp5_global_state *state =3D mdp5_get_global_state(s); + struct mdp5_global_state *state; struct mdp5_hw_pipe_state *new_state; =20 if (!hwpipe) return 0; =20 + state =3D mdp5_get_global_state(s); if (IS_ERR(state)) return PTR_ERR(state); =20 --=20 2.35.1