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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 165F1C433EF for ; Mon, 14 Feb 2022 10:22:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237161AbiBNKWc (ORCPT ); Mon, 14 Feb 2022 05:22:32 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:49688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346753AbiBNKUl (ORCPT ); Mon, 14 Feb 2022 05:20:41 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 057137C7B5; Mon, 14 Feb 2022 01:55:15 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id 60DC0B80DC8; Mon, 14 Feb 2022 09:55:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A595C340E9; Mon, 14 Feb 2022 09:55:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644832511; bh=QtDiWEcSmKNrDcBtsN8v0rSVjLkbZyrSSGtXPtH3eQQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e/tJqyLrQstZ2+t9nh8v4B6QqmBW3YzvvVhP6WGX7inzyt5/6CJwY4eHn4CoYtWYH 1BxXsReS6VNgn+ES7TkuUC2+klRl0P5un8MC8umBRfxfmhNiHJkyB5woRpuSD2hsAR 7HqqVVA4qcuLj6oCJkWBc67S03+daPCGtShuEMnM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Padmanabha Srinivasaiah , Maxime Ripard , Sasha Levin Subject: [PATCH 5.16 036/203] drm/vc4: Fix deadlock on DSI device attach error Date: Mon, 14 Feb 2022 10:24:40 +0100 Message-Id: <20220214092511.434199460@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220214092510.221474733@linuxfoundation.org> References: <20220214092510.221474733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Padmanabha Srinivasaiah [ Upstream commit 0a3d12ab5097b1d045e693412e6b366b7e82031b ] DSI device attach to DSI host will be done with host device's lock held. Un-registering host in "device attach" error path (ex: probe retry) will result in deadlock with below call trace and non operational DSI display. Startup Call trace: [ 35.043036] rt_mutex_slowlock.constprop.21+0x184/0x1b8 [ 35.043048] mutex_lock_nested+0x7c/0xc8 [ 35.043060] device_del+0x4c/0x3e8 [ 35.043075] device_unregister+0x20/0x40 [ 35.043082] mipi_dsi_remove_device_fn+0x18/0x28 [ 35.043093] device_for_each_child+0x68/0xb0 [ 35.043105] mipi_dsi_host_unregister+0x40/0x90 [ 35.043115] vc4_dsi_host_attach+0xf0/0x120 [vc4] [ 35.043199] mipi_dsi_attach+0x30/0x48 [ 35.043209] tc358762_probe+0x128/0x164 [tc358762] [ 35.043225] mipi_dsi_drv_probe+0x28/0x38 [ 35.043234] really_probe+0xc0/0x318 [ 35.043244] __driver_probe_device+0x80/0xe8 [ 35.043254] driver_probe_device+0xb8/0x118 [ 35.043263] __device_attach_driver+0x98/0xe8 [ 35.043273] bus_for_each_drv+0x84/0xd8 [ 35.043281] __device_attach+0xf0/0x150 [ 35.043290] device_initial_probe+0x1c/0x28 [ 35.043300] bus_probe_device+0xa4/0xb0 [ 35.043308] deferred_probe_work_func+0xa0/0xe0 [ 35.043318] process_one_work+0x254/0x700 [ 35.043330] worker_thread+0x4c/0x448 [ 35.043339] kthread+0x19c/0x1a8 [ 35.043348] ret_from_fork+0x10/0x20 Shutdown Call trace: [ 365.565417] Call trace: [ 365.565423] __switch_to+0x148/0x200 [ 365.565452] __schedule+0x340/0x9c8 [ 365.565467] schedule+0x48/0x110 [ 365.565479] schedule_timeout+0x3b0/0x448 [ 365.565496] wait_for_completion+0xac/0x138 [ 365.565509] __flush_work+0x218/0x4e0 [ 365.565523] flush_work+0x1c/0x28 [ 365.565536] wait_for_device_probe+0x68/0x158 [ 365.565550] device_shutdown+0x24/0x348 [ 365.565561] kernel_restart_prepare+0x40/0x50 [ 365.565578] kernel_restart+0x20/0x70 [ 365.565591] __do_sys_reboot+0x10c/0x220 [ 365.565605] __arm64_sys_reboot+0x2c/0x38 [ 365.565619] invoke_syscall+0x4c/0x110 [ 365.565634] el0_svc_common.constprop.3+0xfc/0x120 [ 365.565648] do_el0_svc+0x2c/0x90 [ 365.565661] el0_svc+0x4c/0xf0 [ 365.565671] el0t_64_sync_handler+0x90/0xb8 [ 365.565682] el0t_64_sync+0x180/0x184 Signed-off-by: Padmanabha Srinivasaiah Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20220118005127.29015-1-treasure4paddy@gmail.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/vc4/vc4_dsi.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index a229da58962a2..9300d3354c512 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -1262,7 +1262,6 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *device) { struct vc4_dsi *dsi = host_to_dsi(host); - int ret; dsi->lanes = device->lanes; dsi->channel = device->channel; @@ -1297,18 +1296,15 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host, return 0; } - ret = component_add(&dsi->pdev->dev, &vc4_dsi_ops); - if (ret) { - mipi_dsi_host_unregister(&dsi->dsi_host); - return ret; - } - - return 0; + return component_add(&dsi->pdev->dev, &vc4_dsi_ops); } static int vc4_dsi_host_detach(struct mipi_dsi_host *host, struct mipi_dsi_device *device) { + struct vc4_dsi *dsi = host_to_dsi(host); + + component_del(&dsi->pdev->dev, &vc4_dsi_ops); return 0; } @@ -1686,9 +1682,7 @@ static int vc4_dsi_dev_remove(struct platform_device *pdev) struct device *dev = &pdev->dev; struct vc4_dsi *dsi = dev_get_drvdata(dev); - component_del(&pdev->dev, &vc4_dsi_ops); mipi_dsi_host_unregister(&dsi->dsi_host); - return 0; } -- 2.34.1