From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D9973BE654 for ; Tue, 7 Apr 2026 14:25:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775571947; cv=none; b=Eg3XD8pJO1sdT0SDN0SUoU9ZXjZZ0iQgAz2bHISMUFKq3Y5K1Ni4V5I3aW2x87pXX19wKavvi/nhbOx3c6P4jTczZTFGq7O8y+VSbVImh87wlWw0Rigskg6csDVlfbEvVqUuif2Oy+DNQ7ckXM8Y+klrc3+WjcUC0T2oQ3goNpM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775571947; c=relaxed/simple; bh=oagBiGn9yap490aPu+qNXgOoV9AQzMDW831Ks4zUb1I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ASW+bANWVCoGqLZ+HnkGv3EzCeY2qzkAkeDEo3iP1ma+rVWKYHdFNak1pW9cq5M2RVTWvsD1HRHKEFaaeEn3BorT/jP2s2U0hQzfcoT/Yjme8/wEGBXHuH3DIygkfilZ+HGNg6Ktsgg3p5KPG5X76SyruVn1Ey4lEt9SI3Tq+Q4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=lC7BsgYN; arc=none smtp.client-ip=209.85.221.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lC7BsgYN" Received: by mail-wr1-f43.google.com with SMTP id ffacd0b85a97d-43cf5f6d2eeso196511f8f.0 for ; Tue, 07 Apr 2026 07:25:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775571945; x=1776176745; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=XuC322jDmAgsELlQ3uSNloCGDfnK1HdiuXq+p7r0feg=; b=lC7BsgYNcy4+JBJWiS0eBoyzoUctNxNl2xV+NfJdYwnbbsossStaA4yBr64c767fEO 3AJeaHx61dZGAbmmab3gub+7PEiXpWDC5Ae53cBMK/60Ahq4WSi0Qz7Lx5/Kbp2iX2IX Z1idOF31vHYbkKwSVMDlg3/vB4DTQmP7e5V8n7sQi2Rz6ZLRz/5cbbdVcHAS5A8Ldu18 ArHR7bw7ZPegsv6SGB2PiJxgsgvztq0+X1x0v9HjUwRJI1Gad8t1B/PNYYuJqO+emPZh YjwX+jHQ31VII6HgW5T06MFMZ5wPM2NORAIsS2PustKfEt0iSM+Y44O5I9Rwv89IFcOI ibKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775571945; x=1776176745; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=XuC322jDmAgsELlQ3uSNloCGDfnK1HdiuXq+p7r0feg=; b=OUgzbC2qdBDFVqRIuU/Xg3tmt3EgHKT7sZG9efqNcMa5FkzaxxhUSg1eP7irK5lXRN hfZCMDB+KZnAzRIp5KWQfFiadog1heG8YzS1sSn+QUpdd7PayQveqGo+gboqkrkGkpgu 4PU257mlyvYlAmTHYOWd7Xd1kYdRwUx2XM8WTagA28jqJGIfN0jIyMouEsQXZDn1/wyY K5fHDoBjYiNO6PtBqVN5GAXOnHLARv7c4CC6f0JWmJlCYoDwqmZgr+fKBOFXuuGQky9D dm0+1NZqDkHIMtKlci5xzYYOl6v1lIIkSqLqjNnDxGUK9wtN2gA2ejPWEodGu/anM0yD 0UKw== X-Forwarded-Encrypted: i=1; AJvYcCWfH1YbgjK88dLAB+VbKbO8m/7J5XuMGeMTu/rYo5xnXFpDLQnMW6cus46XpjMjJTlWzyX28Eq0COde3nA=@vger.kernel.org X-Gm-Message-State: AOJu0YxH06uwXjIkaG00SqwPqPCkNjCGNdDyE/fDKFYpHRBgIIGKq1P+ s6c2akqModFRQtmPQfVvEJUBlBAWq3FLUNlTTmuOLsl7V9hP7pN6gImN X-Gm-Gg: AeBDieub9udbQMi3oU5p8GWPN7kc9DMu1Pxb8rGFS4AgGuNPqbSrE0FyMMdKrBAFAHq gCilWcBG9dtrN/TZhDJnIb+4KP1gEsQlEiHoVTtHjNYSHY6BBy2+rSHeaPRglU8Yq8qHdrM7pO6 vKQ83fr85PPjySbd26migD3pD+9Zh9k624c9bQs6Ymm3wdnZ20rW6Y0gr0gprtzSXqppa7yq5Ji +GLX62oSyW+9cvJNjxVvkAvpP7bEwxg3YpzinxW56B7pZnELGaKGxYmWjfjbD5BDJKA/5eblUFA mH4R73qS4+adQWeWNjzY1M7CGpsIMmzukjNi7ckWVO9g4RnrujotEUVmUQrYGnClB80Ew4vP6P+ kQ/vKhrYXNWfaXRAQdqNvbxptFD23YkMuz/VHq0nialgDIbVORuemOeNSSZQqoZFjvKhUbECImV 76JhllaK3vjbxk54Cmqc4AywMy/yl/KWUsu/8tlskK7nPmfIs5zG1EAd4aOJEutQ== X-Received: by 2002:a05:6000:645:b0:43d:284d:28c with SMTP id ffacd0b85a97d-43d292f53a6mr8996744f8f.7.1775571944791; Tue, 07 Apr 2026 07:25:44 -0700 (PDT) Received: from localhost.localdomain ([31.7.38.28]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43d1e4f1a99sm53489990f8f.32.2026.04.07.07.25.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Apr 2026 07:25:44 -0700 (PDT) From: Emre Cecanpunar To: platform-driver-x86@vger.kernel.org Cc: hansg@kernel.org, ilpo.jarvinen@linux.intel.com, linux-kernel@vger.kernel.org, krishna.chomal108@gmail.com, edip@medip.dev, emreleno@gmail.com Subject: [PATCH v4 5/5] platform/x86: hp-wmi: add locking for concurrent hwmon access Date: Tue, 7 Apr 2026 17:25:14 +0300 Message-ID: <20260407142515.20683-6-emreleno@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260407142515.20683-1-emreleno@gmail.com> References: <20260407142515.20683-1-emreleno@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit hp_wmi_hwmon_priv.mode and .pwm are written by hp_wmi_hwmon_write() in sysfs context and read by hp_wmi_hwmon_keep_alive_handler() in a workqueue. A concurrent write and keep-alive expiry can observe an inconsistent mode/pwm pair (e.g. mode=MANUAL with a stale pwm). Add a mutex to hp_wmi_hwmon_priv protecting mode and pwm. Hold it in hp_wmi_hwmon_write() across the field update and apply call, and in hp_wmi_hwmon_keep_alive_handler() before calling apply. In hp_wmi_hwmon_read(), only the pwm_enable path reads priv->mode; use scoped_guard() there to avoid holding the lock across unrelated WMI calls. Fixes: c203c59fb5de ("platform/x86: hp-wmi: implement fan keep-alive") Suggested-by: Ilpo Järvinen Signed-off-by: Emre Cecanpunar --- Changes in v4: - Use devm_mutex_init() and handle init errors. drivers/platform/x86/hp/hp-wmi.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c index 4f49861d3fbe..470c6e48f8e9 100644 --- a/drivers/platform/x86/hp/hp-wmi.c +++ b/drivers/platform/x86/hp/hp-wmi.c @@ -453,6 +453,7 @@ enum pwm_modes { }; struct hp_wmi_hwmon_priv { + struct mutex lock; /* protects mode, pwm */ u8 min_rpm; u8 max_rpm; int gpu_delta; @@ -2422,6 +2423,7 @@ static int hp_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, { struct hp_wmi_hwmon_priv *priv; int rpm, ret; + u8 mode; priv = dev_get_drvdata(dev); switch (type) { @@ -2445,11 +2447,13 @@ static int hp_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, *val = rpm_to_pwm(rpm / 100, priv); return 0; } - switch (priv->mode) { + scoped_guard(mutex, &priv->lock) + mode = priv->mode; + switch (mode) { case PWM_MODE_MAX: case PWM_MODE_MANUAL: case PWM_MODE_AUTO: - *val = priv->mode; + *val = mode; return 0; default: /* shouldn't happen */ @@ -2467,6 +2471,7 @@ static int hp_wmi_hwmon_write(struct device *dev, enum hwmon_sensor_types type, int rpm; priv = dev_get_drvdata(dev); + guard(mutex)(&priv->lock); switch (type) { case hwmon_pwm: if (attr == hwmon_pwm_input) { @@ -2535,6 +2540,8 @@ static void hp_wmi_hwmon_keep_alive_handler(struct work_struct *work) dwork = to_delayed_work(work); priv = container_of(dwork, struct hp_wmi_hwmon_priv, keep_alive_dwork); + + guard(mutex)(&priv->lock); /* * Re-apply the current hwmon context settings. * NOTE: hp_wmi_apply_fan_settings will handle the re-scheduling. @@ -2591,6 +2598,10 @@ static int hp_wmi_hwmon_init(void) if (!priv) return -ENOMEM; + ret = devm_mutex_init(dev, &priv->lock); + if (ret) + return ret; + ret = hp_wmi_setup_fan_settings(priv); if (ret) return ret; -- 2.53.0