From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A35CE3D981; Wed, 21 Feb 2024 14:18:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708525130; cv=none; b=X+ZEITeBfJQ/ERFfMp9wA0gNTKfFU7fDxM5KMLWtLhVtMBDJAZn4mOKUCjnd8eYMDlFsv70C08TytCH7cZFOeQJGWdr5YuWZx4Luy554sOiAU168PELI1bnemL8GjLSJTXKcYvMaBEeeFHbq2PEmBH2fbXymNVQ51q8HxLb4690= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708525130; c=relaxed/simple; bh=Xv70nnC0Mtvhb5NXj5hfzjTDAd6m0Y6c6tDKZeNfq/g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pXnZ7YGDrFy7arh0JBAx3JX9SJ9wFWmP4dKK8DAu1IeCURuwPeCMfM0ibMH5PQ3QQOvZU1ZY6ycH1SCeNaoQNiha6rJfC64qw0kj5AHJK4lSy35tYpDi7WdXOEWGGMymfZqQNcdwt6YdlGX3qPj+khp6z3sliw7w5BYoYx7VSXA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nW8vVoMH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nW8vVoMH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15EAFC433C7; Wed, 21 Feb 2024 14:18:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708525130; bh=Xv70nnC0Mtvhb5NXj5hfzjTDAd6m0Y6c6tDKZeNfq/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nW8vVoMH+aeJM12JwrtypnchnKnbWgFjlm3hIgK8JORFhMDirUV+zFdYw7Ti8xuVz FCYnPa/q2j2qGX8h1qulipw2qMOxq/EduTjWyEt5w3n+cFsLAAAYnaCVJwDEQX3GcW eS8K2w0dDKqsx+tblUx1v9gzEvVyxtjkyeZqF444= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Rui Zhang , Mark Brown , Sasha Levin Subject: [PATCH 5.4 068/267] regulator: core: Only increment use_count when enable_count changes Date: Wed, 21 Feb 2024 14:06:49 +0100 Message-ID: <20240221125942.123422346@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240221125940.058369148@linuxfoundation.org> References: <20240221125940.058369148@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rui Zhang [ Upstream commit 7993d3a9c34f609c02171e115fd12c10e2105ff4 ] The use_count of a regulator should only be incremented when the enable_count changes from 0 to 1. Similarly, the use_count should only be decremented when the enable_count changes from 1 to 0. In the previous implementation, use_count was sometimes decremented to 0 when some consumer called unbalanced disable, leading to unexpected disable even the regulator is enabled by other consumers. With this change, the use_count accurately reflects the number of users which the regulator is enabled. This should make things more robust in the case where a consumer does leak references. Signed-off-by: Rui Zhang Link: https://lore.kernel.org/r/20231103074231.8031-1-zr.zhang@vivo.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/regulator/core.c | 56 +++++++++++++++++++++------------------- 1 file changed, 30 insertions(+), 26 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 87d0cd6f49ca..894915892eaf 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -2658,7 +2658,8 @@ static int _regulator_enable(struct regulator *regulator) /* Fallthrough on positive return values - already enabled */ } - rdev->use_count++; + if (regulator->enable_count == 1) + rdev->use_count++; return 0; @@ -2736,37 +2737,40 @@ static int _regulator_disable(struct regulator *regulator) lockdep_assert_held_once(&rdev->mutex.base); - if (WARN(rdev->use_count <= 0, + if (WARN(regulator->enable_count == 0, "unbalanced disables for %s\n", rdev_get_name(rdev))) return -EIO; - /* are we the last user and permitted to disable ? */ - if (rdev->use_count == 1 && - (rdev->constraints && !rdev->constraints->always_on)) { - - /* we are last user */ - if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) { - ret = _notifier_call_chain(rdev, - REGULATOR_EVENT_PRE_DISABLE, - NULL); - if (ret & NOTIFY_STOP_MASK) - return -EINVAL; - - ret = _regulator_do_disable(rdev); - if (ret < 0) { - rdev_err(rdev, "failed to disable\n"); - _notifier_call_chain(rdev, - REGULATOR_EVENT_ABORT_DISABLE, + if (regulator->enable_count == 1) { + /* disabling last enable_count from this regulator */ + /* are we the last user and permitted to disable ? */ + if (rdev->use_count == 1 && + (rdev->constraints && !rdev->constraints->always_on)) { + + /* we are last user */ + if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) { + ret = _notifier_call_chain(rdev, + REGULATOR_EVENT_PRE_DISABLE, + NULL); + if (ret & NOTIFY_STOP_MASK) + return -EINVAL; + + ret = _regulator_do_disable(rdev); + if (ret < 0) { + rdev_err(rdev, "failed to disable\n"); + _notifier_call_chain(rdev, + REGULATOR_EVENT_ABORT_DISABLE, + NULL); + return ret; + } + _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE, NULL); - return ret; } - _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE, - NULL); - } - rdev->use_count = 0; - } else if (rdev->use_count > 1) { - rdev->use_count--; + rdev->use_count = 0; + } else if (rdev->use_count > 1) { + rdev->use_count--; + } } if (ret == 0) -- 2.43.0