From nobody Mon Nov 25 07:59:35 2024 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E63B1863F for ; Tue, 29 Oct 2024 02:10:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.61.82.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730167844; cv=none; b=rKmMCnq0a9z90tnH+8hkdJJ2FyVf2mMjC0il7V9O7x6KUnaihYXVCnrWL/tbmTvROlcDSXqI4vEZAwoqSfLfXckiLt03U/X2IfFCsTkAn7UFykmdiYR9fPYtEe+fWCDSXupk8FQVnjZfBSmECTgCCiFkGeYk5XoJU98CHodWvso= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730167844; c=relaxed/simple; bh=wW55nxX4enWaaTudNJgiNp6sn8oEZdiWDe5jGNPBVZo=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=BVABDSAlVEUn6WcbTAAaKXEZnW0FGIwhZR0A4oEURsZxdwmzaSBhTAuGnHcsbZPyrWzjbQIZmu+pRQFXyebsOWLN90eIKpOtAPFme9NsYU/K4xN+i7HRX1L788vnCLTVOcKBbBwWoaY9opjE/sw2Ll67jkegKUb57n3TvpbPDMM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com; spf=pass smtp.mailfrom=mediatek.com; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b=QEaj7Kyd; arc=none smtp.client-ip=210.61.82.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mediatek.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="QEaj7Kyd" X-UUID: f867b6fe959a11efbd192953cf12861f-20241029 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=9zxNMXwPCBjYW69Zb32ChS7Lih5KnlHYyLjDjWcKxkQ=; b=QEaj7KydGUhLAKlkeeb1fbsfSA3lBfm6BfmCH/sp8PpzkR+FR3vR8Et9DqlIBq18YzI7vdiybWL1fMi6FtfaSHhxsR7kJu1fMZ44XC/YZXhPHhrmeXgGd/nYhYTucPlaqAWaL7g04ahVMne3Tj6iumjCX4L+GOhXqTJY9TOIgew=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.42,REQID:5356925a-d4ee-438b-9362-cbd31065dccf,IP:0,U RL:0,TC:0,Content:-20,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:-20 X-CID-META: VersionHash:b0fcdc3,CLOUDID:a97933e7-cb6b-4a59-bfa3-98f245b4912e,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:1,EDM:-3,IP:nil,U RL:11|1,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES :1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 0 X-CID-BAS: 0,_,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_ULN X-UUID: f867b6fe959a11efbd192953cf12861f-20241029 Received: from mtkmbs14n2.mediatek.inc [(172.21.101.76)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 568546268; Tue, 29 Oct 2024 10:10:29 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by MTKMBS09N2.mediatek.inc (172.21.101.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Mon, 28 Oct 2024 19:10:28 -0700 Received: from mbjsdccf07.gcn.mediatek.inc (10.15.20.246) by mtkmbs11n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Tue, 29 Oct 2024 10:10:27 +0800 From: mtk25126 To: Alexandre Belloni , Matthias Brugger , AngeloGioacchino Del Regno CC: , , , , , , , , mtk25126 Subject: [PATCH] i3c: Remove redundant lock in i3c_device_uevent Date: Tue, 29 Oct 2024 10:09:40 +0800 Message-ID: <20241029020950.31053-1-defa.li@mediatek.com> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" We encountered the following lockdep warning. The i3c_master_register function recursively acquires &i3cbus->lock twice, which may cause a deadlock.=20 Remove the logic of obtaining i3cbus->lock when using the i3c_device_uevent function to obtain the i3c_device_info structure. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D WARNING: possible recursive locking detected 6.11.0-mainline -------------------------------------------- init/1 is trying to acquire lock: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_bus_normaluse_lock but task is already holding lock: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&i3cbus->lock); lock(&i3cbus->lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by init/1: #0: fcffff809b6798f8 (&dev->mutex){....}-{3:3}, at: __driver_attach #1: f1ffff80a6a40dc0 (&i3cbus->lock){++++}-{3:3}, at: i3c_master_register stack backtrace: CPU: 6 UID: 0 PID: 1 Comm: init Call trace: dump_backtrace+0xfc/0x17c show_stack+0x18/0x28 dump_stack_lvl+0x40/0xc0 dump_stack+0x18/0x24 print_deadlock_bug+0x388/0x390 __lock_acquire+0x18bc/0x32ec lock_acquire+0x134/0x2b0 down_read+0x50/0x19c i3c_bus_normaluse_lock+0x14/0x24 i3c_device_get_info+0x24/0x58 i3c_device_uevent+0x34/0xa4 dev_uevent+0x310/0x384 kobject_uevent_env+0x244/0x414 kobject_uevent+0x14/0x20 device_add+0x278/0x460 device_register+0x20/0x34 i3c_master_register_new_i3c_devs+0x78/0x154 i3c_master_register+0x6a0/0x6d4 mtk_i3c_master_probe+0x3b8/0x4d8 platform_probe+0xa0/0xe0 really_probe+0x114/0x454 __driver_probe_device+0xa0/0x15c driver_probe_device+0x3c/0x1ac __driver_attach+0xc4/0x1f0 bus_for_each_dev+0x104/0x160 driver_attach+0x24/0x34 bus_add_driver+0x14c/0x294 driver_register+0x68/0x104 __platform_driver_register+0x20/0x30 init_module+0x20/0xfe4 do_one_initcall+0x184/0x464 do_init_module+0x58/0x1ec load_module+0xefc/0x10c8 __arm64_sys_finit_module+0x238/0x33c invoke_syscall+0x58/0x10c el0_svc_common+0xa8/0xdc do_el0_svc+0x1c/0x28 el0_svc+0x50/0xac el0t_64_sync_handler+0x70/0xbc el0t_64_sync+0x1a8/0x1ac Signed-off-by: mtk25126 --- drivers/i3c/master.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 6f3eb710a75d..bb8a8bf0c4c7 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -282,7 +282,8 @@ static int i3c_device_uevent(const struct device *dev, = struct kobj_uevent_env *e struct i3c_device_info devinfo; u16 manuf, part, ext; =20 - i3c_device_get_info(i3cdev, &devinfo); + if (i3cdev->desc) + devinfo =3D i3cdev->desc->info; manuf =3D I3C_PID_MANUF_ID(devinfo.pid); part =3D I3C_PID_PART_ID(devinfo.pid); ext =3D I3C_PID_EXTRA_INFO(devinfo.pid); --=20 2.46.0