From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f54.google.com (mail-oo1-f54.google.com [209.85.161.54]) (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 D39B343CE70 for ; Mon, 14 Sep 2026 10:41:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789382506; cv=none; b=p8IPwJ5wCMV/YVLZoCNVDuK3x4kiOZS10csvMulQMaumEfhmvXRKPZRyCNG6s6k2BEBHFhgID4RdpXNvN3KFERiTodUEAqaTyN9dmVYPj5v/BmWgtVoHvpEgbyKg0/yZWPClxrR3s7JCe7RmToXW5xhLSq7S6osVlw5SOuxzmO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789382506; c=relaxed/simple; bh=8RMjW2GZiFLdZ5ZhXAK6hKwmt70RrGO/ubTXCPobtc8=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=uJ1nScumdzDD9zqJrZiUbh5AnjY18M6MKdVuQXm8PapelTrP3dNwj6gv+8RtPTFNzFOITbTn51c8O5suk/huX4eXjl1iYkoi/wPXJMZkhOzJwNVeJozxqIs/WzgZYv6lrFnCR3e7KXVanEIA6Fc0ecSDCvaxMEl06VYLoR0dIIg= 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=fncPsz6e; arc=none smtp.client-ip=209.85.161.54 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="fncPsz6e" Received: by mail-oo1-f54.google.com with SMTP id 006d021491bc7-6aa9606ddadso2630768eaf.0 for ; Mon, 14 Sep 2026 03:41:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789382504; x=1789987304; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=VeYhK5Bct0822vB0fqa5xHImLPh+u4sb5Rd0DXecL4M=; b=fncPsz6e+TJPGaLubeOK2THYTbEXgq+KHuDX5sxHfEH8kYwIoDrjy0jsfR7eGO1qD+ gfJmomiCJLKwgYJpt0Ko2h5XpUJrs0RJnTeUt9MzUrDn5j+43p3Au1Kt9YEvrIeEkG22 OeGVQ0P/Mf8wBuThBzAT/ILl5LpEwoPR/zhdCXtR7m7SHKMdCNMdfkKEre8Dt3cB47+j VYOQNpffM95Gk59jGI9lMdBaEGIh8qjht+FUPyZNuHwFTeWA3yEShUcm9ApQVXkDZAbg hZdh17WyJ+mTScVjauk/z5riZ8BpP8uuytu7caymRAtL184l1bkxdQqDZ8X8WtZ7W7Ze sdDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789382504; x=1789987304; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=VeYhK5Bct0822vB0fqa5xHImLPh+u4sb5Rd0DXecL4M=; b=bS585h1p681nSnS6QmpOxAomowKUbFRKegs3JX34r+MOpEEWrPVH3+T6iP/NtUo3E/ e+iA1gHA+viNl8Or0ZI8ETddCYs30IodmtkLG3hY5wQx4i5xQC4VkaNzF0VDtU96Pvnv 8BHun4vLYmneF+gHcIArqWJXD52mJSytgDfIbti5L5keA+9d443EZzph8h3+7mYTRN7j 0yfqVjSUK88qz7iq4LCr0go0TKo9AcMyWPg3SdICw80/6Or9ynhtqagGXVvRX3Hkzcwl 17wCdbxSLjhhxufKNjMT1Bb6FLch2eYnyPWd4rofuhzg1IJBQl404IzsfekMr0RLoVxp aF2A== X-Forwarded-Encrypted: i=1; AKwUvBydWZEzmbcLKUBJ76tUqwsGXz/GvZWds/xBXXEn9Kr3QFNs6jO1nsUAXJ6Z1SKmaKfCjzGGKS9pqpR0WtI=@vger.kernel.org X-Gm-Message-State: AFuF++k9JA+icMAuDZT9GBWOx9gQpSejemYOghSnXLOypPxR/ydKmCBC M/CVJifr6cdpwFSXi63NrnC70ydW2mJ1rOy08rsvvzdEdTKJkFEoxE0H X-Gm-Gg: AYBFou2ZGzXJlTZWupRWhrbMIe5IZC5vHVkifzbb2peb6jVhJ1wUFfbtKb4nW+PyaiI 7Kf36r1xpO86JVlkxWSFcvRlHrmfgQ13Rni0LVSnvUjsa48f+fnafa9xq/6W453FP/KTUKWuW88 M6McfRxDjLrvXFOzmlvr7irb4muMj8z9X/nMR5PA8QICoHZYbNzPYACv1Nx5saR7enkI20RZ5Jc NXYU0s9bI8+/fzM+YzBEM5vRoQI3Tpco5J7aGE+7fHxdAR5ICjNOJ3u7/BLc7MvCwkKETa15XQN FlBhB3D3oClzDTvh//avQHc7bpACVpJIpZTlJEdFwZpscRM4yrx8o7yzfDcGjlUV4/2grSlZlBl Pb/5P2K3H20XZ0QRrpWMPEF02drHwJ3PY2RDQi9BOwo2hq4ssccmRrsBHTfno3N70uyXWZ+Fgm2 3eCZBMzzAtizdOJ0UW3ya8+WEAJInAI2X0TDzYWf/AjilXogS+blN9qbRK+rz9Rys2aAPYrfBH7 aop0yb0RKlGmyhB X-Received: by 2002:a05:6820:81c5:b0:6b7:8415:d77e with SMTP id 006d021491bc7-6c541f45b3bmr748644eaf.41.1789382503583; Mon, 14 Sep 2026 03:41:43 -0700 (PDT) Received: from SGN-LDSENG.tasernet.com ([2405:4800:5cc3:11a:1ac0:4dff:fe8b:4a69]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-14365b347e6sm23213037c88.4.2026.09.14.03.41.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Sep 2026 03:41:43 -0700 (PDT) From: Cong Nguyen To: Guenter Roeck Cc: Simon Guinot , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] hwmon: (gpio-fan) return IRQ_HANDLED from the shared alarm IRQ handler Date: Mon, 14 Sep 2026 17:41:36 +0700 Message-Id: <20260914104136.1797979-1-congnt264@gmail.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit fan_alarm_irq_handler() always schedules alarm_work but returns IRQ_NONE, so the kernel treats every alarm interrupt as unhandled. On a shared line that risks the whole line being disabled as spurious. v1 just fixed that, but it was still IRQF_SHARED, and always returning IRQ_HANDLED there defeats spurious-interrupt detection for the line -- if the interrupt ever fires without a real event, nothing catches it, and a fault could spin the CPU in the handler. Sashiko flagged this in v1, and Guenter confirmed: this interrupt must not be shared. So v2 drops IRQF_SHARED too. Fixes: d6fe1360f42e ("hwmon: add generic GPIO fan driver") Reported-by: Sashiko AI review Link: https://lore.kernel.org/r/20260901160931.DD3811F00A3D@smtp.kernel.org Assisted-by: Claude:claude-opus-4 Signed-off-by: Cong Nguyen --- Changes in v2: - Also drop IRQF_SHARED (Guenter): always returning IRQ_HANDLED on a still-shared line defeats spurious-interrupt detection for it. v2 is a full patch with both fixes, not a delta on top of v1. drivers/hwmon/gpio-fan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index 084828e1e281..0dbd07f5dc53 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -67,7 +67,7 @@ static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id) schedule_work(&fan_data->alarm_work); - return IRQ_NONE; + return IRQ_HANDLED; } static ssize_t fan1_alarm_show(struct device *dev, @@ -97,7 +97,7 @@ static int fan_alarm_init(struct gpio_fan_data *fan_data) INIT_WORK(&fan_data->alarm_work, fan_alarm_notify); irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH); return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler, - IRQF_SHARED, "GPIO fan alarm", fan_data); + 0, "GPIO fan alarm", fan_data); } /* -- 2.25.1