From patchwork Thu May 5 21:40:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jessica Zhang X-Patchwork-Id: 12840239 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 9A322C433F5 for ; Thu, 5 May 2022 21:41:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239137AbiEEVop (ORCPT ); Thu, 5 May 2022 17:44:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1386011AbiEEVoo (ORCPT ); Thu, 5 May 2022 17:44:44 -0400 Received: from alexa-out-sd-01.qualcomm.com (alexa-out-sd-01.qualcomm.com [199.106.114.38]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD28552E41 for ; Thu, 5 May 2022 14:41:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1651786862; x=1683322862; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=JmZeRu9fqxnrqWyzJlmd4tiyoBFIco93FULPjYt/zDk=; b=qHiYbOmFvavwrDI+RuiNita+Wf3N2Qqku7qBMDoG+TUtntmWkqstNqkG O0PxQhmN+HGQ7Nc0Lz4RlpIWWQIRmslXMcw9FQPboTmq+IuW/UwxiadiS fzXGc3IROQnWYyd87qjd6BhQRSMzGiEd+TI85xW9gOCVoN/ur/hBKGtrd o=; Received: from unknown (HELO ironmsg05-sd.qualcomm.com) ([10.53.140.145]) by alexa-out-sd-01.qualcomm.com with ESMTP; 05 May 2022 14:41:02 -0700 X-QCInternal: smtphost Received: from nasanex01b.na.qualcomm.com ([10.46.141.250]) by ironmsg05-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 14:41:02 -0700 Received: from JESSZHAN.qualcomm.com (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Thu, 5 May 2022 14:41:01 -0700 From: Jessica Zhang To: CC: Jessica Zhang , , , , , , , , , Tomeu Vizoso Subject: [PATCH v3 1/2] drm/msm/mdp5: Return error code in mdp5_pipe_release when deadlock is detected Date: Thu, 5 May 2022 14:40:50 -0700 Message-ID: <20220505214051.155-1-quic_jesszhan@quicinc.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01b.na.qualcomm.com (10.46.141.250) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org mdp5_get_global_state runs the risk of hitting a -EDEADLK when acquiring the modeset lock, but currently mdp5_pipe_release doesn't check for if an error is returned. Because of this, there is a possibility of mdp5_pipe_release hitting a NULL dereference error. To avoid this, let's have mdp5_pipe_release check if mdp5_get_global_state returns an error and propogate that error. Changes since v1: - Separated declaration and initialization of *new_state to avoid compiler warning - Fixed some spelling mistakes in commit message Changes since v2: - Return 0 in case where hwpipe is NULL as this is considered normal behavior - Added 2nd patch in series to fix a similar NULL dereference issue in mdp5_mixer_release Reported-by: Tomeu Vizoso Signed-off-by: Jessica Zhang Reviewed-by: Rob Clark Reviewed-by: Dmitry Baryshkov Reviewed-by: Dmitry Baryshkov --- drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c | 15 +++++++++++---- drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h | 2 +- drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 20 ++++++++++++++++---- 3 files changed, 28 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c index ba6695963aa6..a4f5cb90f3e8 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c @@ -119,18 +119,23 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, return 0; } -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) { struct msm_drm_private *priv = s->dev->dev_private; struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms)); struct mdp5_global_state *state = mdp5_get_global_state(s); - struct mdp5_hw_pipe_state *new_state = &state->hwpipe; + struct mdp5_hw_pipe_state *new_state; if (!hwpipe) - return; + return 0; + + if (IS_ERR(state)) + return PTR_ERR(state); + + new_state = &state->hwpipe; if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx])) - return; + return -EINVAL; DBG("%s: release from plane %s", hwpipe->name, new_state->hwpipe_to_plane[hwpipe->idx]->name); @@ -141,6 +146,8 @@ void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) } new_state->hwpipe_to_plane[hwpipe->idx] = NULL; + + return 0; } void mdp5_pipe_destroy(struct mdp5_hw_pipe *hwpipe) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h index 9b26d0761bd4..cca67938cab2 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h @@ -37,7 +37,7 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, uint32_t caps, uint32_t blkcfg, struct mdp5_hw_pipe **hwpipe, struct mdp5_hw_pipe **r_hwpipe); -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); struct mdp5_hw_pipe *mdp5_pipe_init(enum mdp5_pipe pipe, uint32_t reg_offset, uint32_t caps); diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c index 228b22830970..979458482841 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c @@ -311,12 +311,24 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state, mdp5_state->r_hwpipe = NULL; - mdp5_pipe_release(state->state, old_hwpipe); - mdp5_pipe_release(state->state, old_right_hwpipe); + ret = mdp5_pipe_release(state->state, old_hwpipe); + if (ret) + return ret; + + ret = mdp5_pipe_release(state->state, old_right_hwpipe); + if (ret) + return ret; + } } else { - mdp5_pipe_release(state->state, mdp5_state->hwpipe); - mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); + ret = mdp5_pipe_release(state->state, mdp5_state->hwpipe); + if (ret) + return ret; + + ret = mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); + if (ret) + return ret; + mdp5_state->hwpipe = mdp5_state->r_hwpipe = NULL; }