From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out198-4.us.a.mail.aliyun.com (out198-4.us.a.mail.aliyun.com [47.90.198.4]) (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 39879310771 for ; Wed, 15 Oct 2025 06:51:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=47.90.198.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760511093; cv=none; b=UotUVKctAwCveyOJ7b3KriaJGwnxpNb7CFnYpncFEz2MZ67I8BN1K6Q4VSmnq5dudZ6fGoUbjutwqz/EMK85fuAd+TrVRSE5QZ2aHsjj5YT1WXfZiUQ6g1OfFEa5/FVvUr7S/R4WjwyJrTwtw/AzvOTX6yw/na0ni1pjB1KKByY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760511093; c=relaxed/simple; bh=apkylMRgyanDNynz4jQ9GVpsBDGWQusLXDjccYPVnSE=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=FlbrNGAPd6ml6hhCluz2b7zRhVW8VDfL44P1+trUMeOPh/flZcCpaqvlyPx4COEiNSeJXah9jYlCKa+ec+LxOy+xfkxljRU3DzILlUp6viizuSo0S44DWd9I4dNpwcupB4lgR5OZshSWR40qr5oA3FupvCstKW/tfYEDqrZ4a9w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=allwinnertech.com; spf=pass smtp.mailfrom=allwinnertech.com; arc=none smtp.client-ip=47.90.198.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=allwinnertech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=allwinnertech.com Received: from SunxiBot.allwinnertech.com(mailfrom:michael@allwinnertech.com fp:SMTPD_---.f-xpKI-_1760511065 cluster:ay29) by smtp.aliyun-inc.com; Wed, 15 Oct 2025 14:51:08 +0800 From: Michael Wu To: myungjoo.ham@samsung.com, cw00.choi@samsung.com, andriy.shevchenko@linux.intel.com Cc: linux-kernel@vger.kernel.org Subject: [PATCH v2] extcon: Fixed sysfs duplicate filename issue Date: Wed, 15 Oct 2025 14:51:02 +0800 Message-Id: <20251015065102.70422-1-michael@allwinnertech.com> X-Mailer: git-send-email 2.29.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit With current extcon_dev_unregister() timing, ida_free is before device_unregister(), that may cause current id re-alloc to another device in extcon_dev_register() context but sysfs filename path not removal completed yet. The right timing shows below: on extcon_dev_register: ida_alloc() -> device_register() on extcon_dev_unregister: device_unregister() -> ida_free() stack information when an error occurs: sysfs: cannot create duplicate filename '/class/extcon/extcon1' Call trace: dump_backtrace+0xe8/0x108 show_stack+0x18/0x28 dump_stack_lvl+0x50/0x6c dump_stack+0x18/0x24 sysfs_warn_dup+0x68/0x88 sysfs_do_create_link_sd+0x94/0xdc sysfs_create_link+0x30/0x48 device_add_class_symlinks+0xb4/0x12c device_add+0x1e0/0x48c device_register+0x20/0x34 extcon_dev_register+0x3b8/0x5c4 devm_extcon_dev_register+0x4c/0x94 Fixes: 7bba9e81a6fb ("extcon: Use unique number for the extcon device ID") Cc: Andy Shevchenko Acked-by: MyungJoo Ham Signed-off-by: Michael Wu --- ChangeLog: V1 -> V2: Update commit msg, suggested by Markus Elfring V1: https://lore.kernel.org/all/20251011053719.87055-1-michael@allwinnertech.com/ --- --- drivers/extcon/extcon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c index e7f55c021e562..c08f642d7f5ee 100644 --- a/drivers/extcon/extcon.c +++ b/drivers/extcon/extcon.c @@ -1371,10 +1371,10 @@ void extcon_dev_unregister(struct extcon_dev *edev) return; } - ida_free(&extcon_dev_ids, edev->id); - device_unregister(&edev->dev); + ida_free(&extcon_dev_ids, edev->id); + if (edev->mutually_exclusive && edev->max_supported) { for (index = 0; edev->mutually_exclusive[index]; index++) -- 2.29.0