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 01098C4332F for ; Sun, 18 Dec 2022 16:59:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233109AbiLRQ67 (ORCPT ); Sun, 18 Dec 2022 11:58:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233217AbiLRQ5h (ORCPT ); Sun, 18 Dec 2022 11:57:37 -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 58B221C932; Sun, 18 Dec 2022 08:20:08 -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 1367CB80BA7; Sun, 18 Dec 2022 16:20:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31698C433EF; Sun, 18 Dec 2022 16:20:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380405; bh=T00px381/fymGviS3ig9Kp9XjOfqT0fxgj9n4vgNJI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wf/lR7NSNjeIUITMZNwmUCvFWDNiYvf/0UdD4fWUVm6KQSkcQMREhjlxChNjeuqi4 zQ+FzPYEjuPE7PqWPgnfJIBxHUW35V+31sNnmwOXX7bZgEyUn4m8KgOFyLmNXPAtjT fgMJE9p/OEDZiAFsq6M6DbdKwgJ/8gQEiKPCOZgHwtWDw4gHqePFNxjKqtOeYYyTRd Dkm8n2bLC7zKtO4wywK56VYxSuewqKZyyJwDtasO9JSDVFwGHYwD3VuPXbms5dPsdx 9kTgOxBgo8c5lXiKb3R92wEz8iA+qWrP0ksfUKmWKDzK/Hp//Ilmb/chypR6BdjFfH miAgTjgssCnbg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Rui Zhang , Mark Brown , Sasha Levin , lgirdwood@gmail.com Subject: [PATCH AUTOSEL 5.4 27/30] regulator: core: fix use_count leakage when handling boot-on Date: Sun, 18 Dec 2022 11:18:32 -0500 Message-Id: <20221218161836.933697-27-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218161836.933697-1-sashal@kernel.org> References: <20221218161836.933697-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rui Zhang [ Upstream commit 0591b14ce0398125439c759f889647369aa616a0 ] I found a use_count leakage towards supply regulator of rdev with boot-on option. ┌───────────────────┐ ┌───────────────────┐ │ regulator_dev A │ │ regulator_dev B │ │ (boot-on) │ │ (boot-on) │ │ use_count=0 │◀──supply──│ use_count=1 │ │ │ │ │ └───────────────────┘ └───────────────────┘ In case of rdev(A) configured with `regulator-boot-on', the use_count of supplying regulator(B) will increment inside regulator_enable(rdev->supply). Thus, B will acts like always-on, and further balanced regulator_enable/disable cannot actually disable it anymore. However, B was also configured with `regulator-boot-on', we wish it could be disabled afterwards. Signed-off-by: Rui Zhang Link: https://lore.kernel.org/r/20221201033806.2567812-1-zr.zhang@vivo.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/regulator/core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 7d15312d6792..56b8883c26f9 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1387,7 +1387,13 @@ static int set_machine_constraints(struct regulator_dev *rdev) if (rdev->supply_name && !rdev->supply) return -EPROBE_DEFER; - if (rdev->supply) { + /* If supplying regulator has already been enabled, + * it's not intended to have use_count increment + * when rdev is only boot-on. + */ + if (rdev->supply && + (rdev->constraints->always_on || + !regulator_is_enabled(rdev->supply))) { ret = regulator_enable(rdev->supply); if (ret < 0) { _regulator_put(rdev->supply); -- 2.35.1