From patchwork Wed Dec 14 13:16:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 13073132 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 B935EC2D0CB for ; Wed, 14 Dec 2022 13:19:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238288AbiLNNTG (ORCPT ); Wed, 14 Dec 2022 08:19:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238520AbiLNNTA (ORCPT ); Wed, 14 Dec 2022 08:19:00 -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 12920209AC; Wed, 14 Dec 2022 05:18:57 -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 C3B0DB818BA; Wed, 14 Dec 2022 13:18:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A14FC433EF; Wed, 14 Dec 2022 13:18:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671023934; bh=xwJ2F+HL8Yk0Fx3XqoMXtNfS5GIPd1gzxcsg5dDoon8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QP7v+ZzVI06/yPy1cj0gYDD7mG1of1hKuSt/w5bpOrTOsOETjgUEc6Dxsq65g4/hQ Fjy5ZqjxlEO4FPBy+HmWmxUARSuxIc328Fzp+FLLmftMf0i9OO7JDX0pfLb1AAELxO 4F2oUr73dVKcnjM84Sm1+0uoO332iQyxBEjrQDzgOhOchxhbfaBaP0GiecxfOpt8U7 2RgX4K0g69VvqkFaH3Oy4ffIl4AFigY7gl+xIltPIJbjXCwlSdgufiiDPMDhPmI97X cp5rZOCf/Bmf7NFqdGdEGrwTBsae1YJmG5SHuHSmoPTDEGuXLGZ97M7gAlRE+SBO+a iT520n6hJ8R2Q== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1p5RfO-0000gO-Nm; Wed, 14 Dec 2022 14:19:22 +0100 From: Johan Hovold To: Daniel Lezcano , "Rafael J. Wysocki" Cc: Amit Kucheria , Thara Gopinath , Andy Gross , Bjorn Andersson , Konrad Dybcio , Zhang Rui , Bartlomiej Zolnierkiewicz , Krzysztof Kozlowski , Alim Akhtar , Thierry Reding , Jonathan Hunter , Dmitry Baryshkov , linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-tegra@vger.kernel.org, Johan Hovold Subject: [PATCH 4/4] thermal/drivers/qcom: fix lock inversion Date: Wed, 14 Dec 2022 14:16:17 +0100 Message-Id: <20221214131617.2447-5-johan+linaro@kernel.org> X-Mailer: git-send-email 2.37.4 In-Reply-To: <20221214131617.2447-1-johan+linaro@kernel.org> References: <20221214131617.2447-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org The thermal-zone-device lock is held by core when setting trip points and the driver takes its chip lock in the corresponding callback. Fetching the thermal trip points using thermal_zone_get_trip() also involves taking the thermal-zone-device lock, which means that the chip lock can not be held when doing so. Drop the chip lock temporarily during probe to avoid the lock inversion that was detected by lockdep: ====================================================== WARNING: possible circular locking dependency detected 6.1.0-next-20221213 #122 Not tainted ------------------------------------------------------ systemd-udevd/264 is trying to acquire lock: ffff741e444a0920 (&chip->lock){+.+.}-{3:3}, at: qpnp_tm_get_temp+0xb4/0x1b0 [qcom_spmi_temp_alarm] but task is already holding lock: ffff741e44341618 (&tz->lock){+.+.}-{3:3}, at: thermal_zone_device_update+0x2c/0x70 which lock already depends on the new lock. Fixes: 78c3e2429be8 ("thermal/drivers/qcom: Use generic thermal_zone_get_trip() function") Signed-off-by: Johan Hovold --- drivers/thermal/qcom/qcom-spmi-temp-alarm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c index bfaec74f13b2..e2429676d0d2 100644 --- a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c +++ b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c @@ -348,7 +348,12 @@ static int qpnp_tm_init(struct qpnp_tm_chip *chip) if (stage) chip->temp = qpnp_tm_decode_temp(chip, stage); + mutex_unlock(&chip->lock); + crit_temp = qpnp_tm_get_critical_trip_temp(chip); + + mutex_lock(&chip->lock); + ret = qpnp_tm_update_critical_trip_temp(chip, crit_temp); if (ret < 0) goto out;