From patchwork Thu May 5 21:40:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jessica Zhang X-Patchwork-Id: 570230 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 A675FC433FE for ; Thu, 5 May 2022 21:41:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378725AbiEEVor (ORCPT ); Thu, 5 May 2022 17:44:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1386011AbiEEVoq (ORCPT ); Thu, 5 May 2022 17:44:46 -0400 Received: from alexa-out-sd-02.qualcomm.com (alexa-out-sd-02.qualcomm.com [199.106.114.39]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADDBD52B23 for ; Thu, 5 May 2022 14:41:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1651786865; x=1683322865; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=UqZi48KwBNy4644Kyncmf9QTA2gl1Tw5WUxX1yOFFR8=; b=H2w3RwI2/JThjUFVx5c08wOncbdiUgxQsXOMHmmm4a+gfYem9mcNjMy/ 784EzTT5cXQ6C+R7L4bJ7c+3yoS8obqvAj3OgyhGgabHQtH2K03CY2hMg 0Y+B5R8vFH6SXaJ3r5eixJB2C/XlHU8zVoDU7QWLoR5dXyW/awHYF6Z4P 8=; Received: from unknown (HELO ironmsg04-sd.qualcomm.com) ([10.53.140.144]) by alexa-out-sd-02.qualcomm.com with ESMTP; 05 May 2022 14:41:05 -0700 X-QCInternal: smtphost Received: from nasanex01b.na.qualcomm.com ([10.46.141.250]) by ironmsg04-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 14:41:04 -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 14:41:04 -0700 From: Jessica Zhang To: CC: Jessica Zhang , , , , , , , , , Tomeu Vizoso Subject: [PATCH v3 2/2] drm/msm/mdp5: Return error code in mdp5_mixer_release when deadlock is detected Date: Thu, 5 May 2022 14:40:51 -0700 Message-ID: <20220505214051.155-2-quic_jesszhan@quicinc.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220505214051.155-1-quic_jesszhan@quicinc.com> References: <20220505214051.155-1-quic_jesszhan@quicinc.com> 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 There is a possibility for mdp5_get_global_state to return -EDEADLK when acquiring the modeset lock, but currently global_state in mdp5_mixer_release doesn't check for if an error is returned. To avoid a NULL dereference error, let's have mdp5_mixer_release check if an error is returned and propagate that error. Reported-by: Tomeu Vizoso Signed-off-by: Jessica Zhang --- drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 10 ++++++++-- drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c | 15 +++++++++++---- drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h | 4 ++-- 3 files changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c index b966cd69f99d..fe2922c8d21b 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c @@ -612,9 +612,15 @@ static int mdp5_crtc_setup_pipeline(struct drm_crtc *crtc, if (ret) return ret; - mdp5_mixer_release(new_crtc_state->state, old_mixer); + ret = mdp5_mixer_release(new_crtc_state->state, old_mixer); + if (ret) + return ret; + if (old_r_mixer) { - mdp5_mixer_release(new_crtc_state->state, old_r_mixer); + ret = mdp5_mixer_release(new_crtc_state->state, old_r_mixer); + if (ret) + return ret; + if (!need_right_mixer) pipeline->r_mixer = NULL; } diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c index 954db683ae44..2536def2a000 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c @@ -116,21 +116,28 @@ int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc, return 0; } -void mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer) +int mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer) { struct mdp5_global_state *global_state = mdp5_get_global_state(s); - struct mdp5_hw_mixer_state *new_state = &global_state->hwmixer; + struct mdp5_hw_mixer_state *new_state; if (!mixer) - return; + return 0; + + if (IS_ERR(global_state)) + return PTR_ERR(global_state); + + new_state = &global_state->hwmixer; if (WARN_ON(!new_state->hwmixer_to_crtc[mixer->idx])) - return; + return -EINVAL; DBG("%s: release from crtc %s", mixer->name, new_state->hwmixer_to_crtc[mixer->idx]->name); new_state->hwmixer_to_crtc[mixer->idx] = NULL; + + return 0; } void mdp5_mixer_destroy(struct mdp5_hw_mixer *mixer) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h index 43c9ba43ce18..545ee223b9d7 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h @@ -30,7 +30,7 @@ void mdp5_mixer_destroy(struct mdp5_hw_mixer *lm); int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc, uint32_t caps, struct mdp5_hw_mixer **mixer, struct mdp5_hw_mixer **r_mixer); -void mdp5_mixer_release(struct drm_atomic_state *s, - struct mdp5_hw_mixer *mixer); +int mdp5_mixer_release(struct drm_atomic_state *s, + struct mdp5_hw_mixer *mixer); #endif /* __MDP5_LM_H__ */